Pollster.com

April 13, 2008 - April 19, 2008

 

POLL: Gallup Daily and Rasmussen Daily for 4/19


The Gallup Daily (National)

Clinton 46, Obama 45
Obama 45, McCain 44... Clinton 46, McCain 44

Rasmussen Reports (National)

Obama 45, Clinton 43
McCain 48, Obama 41... McCain 49, Clinton 42
Article

Favorable / Unfavorable
McCain: 56 / 40
Clinton: 45 / 53
Obama: 47 / 51


National Dem Trends, Newsweek Poll

Topics: 2008 , Barack Obama , Exit Polls , Gallup , Hillary Clinton , Newsweek , Pollster

A new Newsweek poll gives Barack Obama a 54%-35% lead over Hillary Clinton among Democratic voters (story here, detailed results here, and thanks to Newsweek and their pollster, Princeton Survey Research Associates International, for a full and complete disclosure of the details of their survey. A model others should be encouraged to follow.)

The Newsweek poll raised a few eyebrows for its 19 point Obama lead, considerably more than other recent polls, and beyond the 10.4 point Obama lead in our trend estimator. However, a closer look at recent data shows that Newsweek is not far from other recent data. Newsweek is the 6th poll in April with Obama at or above 50%, while five April polls put him below 50%. With Clinton, Newsweek is the 4th April poll putting her at or below 40%, while eight polls have her above 40%. So Newsweek shows a larger Obama lead than others, but it is not as far out of line as may first appear. (Note in the counts of polls above, we only count independent samples of the Gallup daily tracker, so dont' count each of their daily results as new polls.)

As you can see from the plots below, we've not seen many recent outliers in the national Democratic nomination polling, and the new Newsweek is well within the 95% confidence interval.

All that said, our trend estimate for the race puts Obama at 50.2% and Clinton at 39.8%, a significant gain for Obama during the month of April. Since late March, Clinton has suffered a somewhat greater downward slope while Obama's gains have been a bit more shallow, implying a slight gain among undecided voters.

The Newsweek poll also has some interesting internal results. As with virtually all this year's polling, Obama has a substantial lead among Independents who will vote in the Democratic primary or who lean Democratic: 61% to 28% for Clinton. What is a key to Obama's strength in the Newsweek poll is he ALSO leads among self-declared Democrats 51% to 38%, a group Clinton has won in most contests. If real (and I want to see more data before I accept this change) then Obama may be winning the consensus among party rank and file that will be key to persuading Superdelegates to move strongly in his direction. So long as he trails among the strongest party identifiers, that case is less persuasive. Pennsylvania provides a new test of this possible change in support. (Obama continues to trail in our Pennsylvania estimates, so it is unlikely he has so far persuaded a majority of Democratic identifiers there, though stay tuned for Tuesday's exit polls.)

The other important shifts in this national Newsweek poll is that Obama leads among men 57%-31% but also among women 52%-38%. Again this would represent an important gain among women.

The age gradient in Obama support has been interesting all year. In the Newsweek poll, he wins 18-39 year olds by 62%-28%, as usual, but also wins 40-59 year olds by 54-36%. In past exit polls, his "break even point" has varied among age groups from as low as 40 (i.e. losing all groups over 40 years old) to as high as 59 (only losing those over 60 years old.). More astonishing here is he gains a plurality of those over 60, 47%-41%, which if true would be his best performance among older voters all year.

The area of the Newsweek poll where Obama still suffers is among working class or poor whites, where he trails badly, 35%-54%. In contrast he leads 52%-35% among upper and middle class whites. That class divide remains a critical issue for his campaign.

A caution here as well. In any poll with such high overall support, the support almost has to reach across many subgroups (not quite as a mathematical certainty, but as a strong empirical regularity.) So we should be careful not to accept the depth of Obama's support among Democrats, women and those over 40 years old until we have more evidence from additional polling. In the exit polls this year, where we see big Obama wins (VA, MD, WI) we also saw him making strong inroads among these groups. But with the margin he achieved in these states, it would have been hard NOT to have done well across groups. Be careful of the cause and effect attributions here. It is a challenging state like Pennsylvania that can reveal how deeply into the various demographic groups Obama has managed to extend his appeal. But with those cautions, Newsweek's poll shows some evidence that the national Democratic constituency is moving in his direction across a number of groups.

If these changes are real, we'll see new polling that reflects it. If just a favorable poll (though not an outlier!) then new polling will show that these groups are not quite as enthusiastic for Obama as the current poll suggested.

Cross posted at PoliticalArithmetik.com


POLL: Newsmax/Zogby Pennsylvania Dems 4/17-18


Zogby/Newsmax

Pennsylvania
4/17 through 4/18, n=608 likely Democratic primary voters
Clinton 47, Obama 42


POLL: Newsweek National


Newsweek
Survey of 1,356 adults, 1,209 registered voters, 586 registered voters that identify or lean Democratic, interviews conducted 4/16-17 (article, results).

National

Among Registered Voters:
Vote Preference:
Obama 48, McCain 44
Clinton 47, McCain 43
Gore 49, McCain 46

Favorable/Unfavorable:
Obama 57/36
Clinton 49/47
McCain 52/42

Among Registered/Dem-Dem Leaners:
Obama 54, Clinton 35 ("Most like to see as Democratic nominee")


Why Weekend Updates May Be Slow

Topics: Pollster.com

Back in September, Eric Dienstfrey, ever the model employee, asked politely if he might be able to take a week off in April for the Passover holiday and to attend to a family obligation.

I said: "April? Please. That should be an easy month." And in a managerial move that was not the most far sighted, I told him it would be fine to take off the week off starting on April 18.

Good planning, huh?

And of course, had I thought about it for a minute, I would have remembered that I would be likely to have travel plans of my own for Passover (which begins tomorrow night), especially given that April 20 is also my parent's 50th wedding anniversary...and my wife's birthday.

So this is a long way of saying that Eric will be off for the next week and in about 15 minutes I'll going offline to enjoy all the pleasures of a six hour drive from Washington, DC to Cleveland Ohio. As such, updates will certainly be infrequent for the rest of the day and over the weekend. Knowing how closely everyone (including yours truly) is following the Pennsylvania primary, I will post and update as often as I can.

Meanwhile, for those alert readers who often email us with the latest survey, please feel free to post comments to this post today with links to any new polls (just remember, no more than 2-3 links per comment or it won't publish).

And finally, if you happen to be dining in Breezewood, PA later tonight and see a guy trying to concentrate on his laptop while his wife and two young kids eat, well, that will probably be me.

[Typos and grammar repaired - and if you see more of such errors than usual this week, you will know another reason we value Eric]


Pollster Effects on Pennsylvania Trends

Topics: 2008 , Barack Obama , Hillary Clinton , Pollster.com , Pollsters , PPP , Quinnipiac , Rasmussen , SurveyUSA , Trend lines , Zogby

There is a lot of interest in the differences among pollsters, and especially what effect they have on the perception of the race. Here at Pollster, the interest is specifically on the question of whether individual pollsters drive our results, and if so by how much.

So here is a quick look at those effects in Pennsylvania's Democratic primary.

The chart above shows the trend estimates that result from dropping each pollster in turn, and reestimating the trend without that pollster. This is a specific test of how much it matters whether we include a particular pollster or not.

Over the 15 pollsters we have represented in Pennsylvania, the estimates excluding each one for Clinton range from 46.6% to 48.3. The estimate with all pollsters included is 47.4% for Clinton.

For Obama, the estimates range from 41.2% to 42.5%, with the estimate for all pollsters at 42.0%.

The upshot is that pollsters do matter, but none drive the results by very much. A 1.7% range on Clinton and a 1.3% range on Obama for the trend estimate is very small compared to the range we see across the raw poll results. Another example of the greater stability of the trend estimators we use compared to the substantial variability across polls.

We can look at the effects of each pollster by comparing the trend estimate without that pollster to the estimate with them. The higher the effect, the more that pollster drives our trend estimate up for that candidate. Negative effects means the pollster drives our estimate down. Again, this is compared to the trend with and without the individual pollster.

The two charts below show these effects for Clinton and for Obama.

For Clinton, SurveyUSA has the highest positive impact on our trend estimate, followed by Rasmussen. At the opposite end, PPP has the largest negative effect on our trend, with Zogby/Newsmax the next largest negative effect. Other pollsters are clustered rather closely around zero.

And it is important to note that even the four largest positive and negative effects are all less that 1 percentage point.

For Obama's trend, Quinnipiac shows the largest positive effect, followed by Zogby and PPP with near identical effects. On the negative end, SurveyUSA has the most negative effect of Obama trend. Again, none of these effects is as much as one percentage point, and SurveyUSA's is less that half a percentage point. Other pollsters have less impact.

We can also look at the joint effects. These are the same as seen individually above but plotted against one another.

Pollsters do matter, and outliers matter even more. But the net effect of any individual pollster on our trend estimates in Pennsylvania are modest, especially when viewed in comparison to the wide range of raw poll results for each candidate. Another advantage of combining information across polls rather than pick single polls we "like".

Cross posted at PoliticalArithmetik.com


Pennsylvania Dem Sensitivity Comparison

Topics: 2008

Here is an update on the Pennsylvania Trend Estimates for both the standard estimator and the more sensitive one.

The difference is small: 0.3 for Clinton and 0.8 for Obama. But hey, it can be a game of inches. Either way it looks like about a 5 point margin right now.

(See earlier posts for details on the standard and sensitive estimate. The sensitive is about twice as responsive to the data, but tends to chase ghosts.)

Cross posted at PoliticalArithmetik.com


POLL: The Daily Rasmussen


Rasmussen Reports

National
Obama 46, Clinton 41
McCain 48, Obama 42... McCain 50, Clinton 41
Article

Favorable / Unfavorable
McCain: 56 / 41
Clinton: 43 / 55
Obama: 47 / 51


POLL: The Daily Gallup


Gallup Poll

National
Obama 47, Clinton 44
Obama 45, McCain 44... Clinton 46, McCain 44

Also
"28% Report Major Changes to Live 'Green'"


POLL: Downs Center/SurveyUSA Indiana Democrats


Mike Downs Center for Indiana Politics/ SurveyUSA

Indiana
n=578 likely Democratic primary voters, fielded April 14-16

President: Obama 50%, Clinton 45%

Governor: Thompson 47%, Schellinger 41%

Crosstabs for

Update: Please note that unlike the survey conducted and released earlier this week by SurveyUSA, this poll survey used a different "sample frame" (one based on a registered voter list rather than random digit dialing). I asked SurveyUSA's Jay Leve to confirm and he sent along a detailed explanation (that appears after the jump) of all the methodological differences between the polls and what may or may not explain the differences in presidential preference on the two surveys.

Continue reading "POLL: Downs Center/SurveyUSA Indiana Democrats"


POLL: Rasmussen Penn Dems


Rasmussen Reports

Pennsylvania
n=730 likely Democratic primary voters, fielded 4/17
Clinton 47%, Obama 44%

Links to article, topline results

[Date corrected -- thanks Thatcher]


POLL: Newsmax/Zogby Pennsylvania Dems 4/16-17

Topics: 2008

Zogby/Newsmax

Pennsylvania 4/16 through 4/17
Clinton 47, Obama 43


POLL: ABC/Post National on Economy/Iraq

Topics: Iraq

More from ABC News/Washington Post poll released yesterday
April 10-13, n=1,197 adults

--90% rate the "state of the nation's economy" as not so good or poor, 10% rate it as excellent or good.

--61% now think "the war on terrorism can be a success without the United States winning the war in Iraq," 31% think the "United States must win the war in Iraq in order for the broader war on terrorism to be a success.

Washington Post:
Results
Article: "Public's View of Economy Takes Fast Turn Downward"

ABC News:
Analysis: "Iraq as a Must-Win Now Rejected by 2-1"
Analysis PDF+Results


POLL: SurveyUSA Statewide GEs


14 new SurveyUSA statewide general election match-ups (conducted 4/11 through 4/13) testing McCain against both Obama and Clinton are now available online.

Changes from last month here.

The state of Virginia here.


POLL: Zogby Pennsylvania Dems


Zogby/Newsmax

Pennsylvania 4/15 through 4/16
Clinton 45, Obama 44

As in previous primary states, Zogby is doing rolling average tracking surveys through election day. So (to answer the question from URI), today's two-day sample overlaps with yesterday's.


Pennsylvania: Follow the Undecided

Topics: 2008 , Divergent Polls

My NationalJournal.com column for the week, on those widely divergent Pennsylvania polls, is now online. As a tease to motivate you to click thru, here's the graphic featured in the column (graphically enhanced by my National Journal colleagues).


080417_blumenthal.gif

I should note that while I was writing this column yesterday, Brian Schaffner was apparently in the midst of creating a scatter plot for his CCPS blog that is eerily similar to the one I did for the column. He gets all due props for getting his posted first.

[I've got some additional thoughts that were too much for the column and will update with those a little later this morning].


"Outliers" for April 16

Topics: 2008 , ABC/Washington Post , Barack Obama , Frank Newport , Kathy Frankovic , Robert Novak , The 2008 Race

Kathy Frankovic sees strong parallels between currently bleak assessments of the president and the economy and those expressed by Americans in 1992 and 1980.

Frank Newport puts on his sociologist's hat and examines Barack Obama's controversial "bitter" comments.

David Hill thinks "young politicians" like Barack Obama need to put less faith in sociology.

Ana Marie Cox sees a different context for the "erosion of trust" results from today's Post/ABC poll.

Jennifer Agiesta reviews data on how white Catholics view the 2008 race.

Jay Cost considers what Barack Obama's performance among white voters may or may not mean to super delegates.

Brian Schaffner continues his three-part series on how the demographics of Pennsylvania compare to other states (and adds a within-state bonus).

Marc Ambinder ponders the Pennsylvania polls and passes on how the campaigns are spinning their internal results.

Robert Novak theorizes why Mark Penn remains on board with the Clinton campaign.

Geoff Garin promises to read a lot of email.

HCD Research posts results from a qualitative test of how voters react to an Obama speech adressing the "bitter" comments (via Sullivan)

Mark Mellman answers an attack by Arianna Huffington on a poll he conducted in the 1990s for Lockheed Martin.

And, in case anyone is wondering, pollsforcongress.com is a candidate, not a research firm.


POLL: TargetPoint Colorado Sen, Pres


TargetPoint/New Leadership USA (R)

Colorado
McCain 51, Obama 39... McCain 52, Clinton 40
Sen: Udall 45, Schaffer 45


POLL: The Daily Rasmussen


Rasmussen Reports

National
Obama 48, Clinton 41
McCain 47, Obama 42... McCain 50, Clinton 40

Favorable / Unfavorable
McCain: 55 / 42
Clinton: 42 / 56
Obama: 47 / 51


POLL: The Daily Gallup


Gallup Poll

National
Obama 50, Clinton 42
Obama 46, McCain 43... Clinton 46, McCain 44

Also
Obama Support Among "Bitter" Voters Unchanged - Video
Poor Economy Ratings Remain Above 40%


POLL: ARG North Carolina Dems


American Research Group

North Carolina
Obama 52, Clinton 41


POLL: PPP Pennsylvania Dems


Public Policy Polling (D)

Pennsylvania
Obama 45, Clinton 42


POLL: Zogby National


Zogby/Reuters

National 4/10 through 4/12
Obama 51, Clinton 38
Obama 45, McCain 45... McCain 46, Clinton 41


POLL: Franklin & Marshall Penn Dems


Franklin & Marshall College/
Philadelphia Daily News
(story, results)

Pennsylvania 4/8 through 4/13
Clinton 49, Obama 42 (with leaners)
Clinton 46, Obama 40 (without leaners)


POLL: ABC/Washington Post National


ABC News/Washington Post
April 10-13, n=1,197 adults

Adults:
Bush as president: 33% approve, 64% disapprove

Registered Voters:
McCain 48%, Clinton 45%
Obama 49%, McCain 44%

Leaned Democrats:
Obama 51%, Clinton 41%

Washington Post:
Results
Article: "Democrats Willing to Let Battle Continue"
Article: "Majority View Clinton as Dishonest"

ABC News:
Analysis
Results


POLL: InsiderAdvantage NC Dems


InsiderAdvantage

North Carolina 4/14
Obama 51, Clinton 36


POLL: Strategic Vision Pennsylvania


Strategic Vision (R)

Pennsylvania 4/11 through 4/13
Clinton 49, Obama 40
McCain 49, Obama 39... McCain 47, Clinton 44


POLL: Times/Bloomberg IN/PA/NC


Los Angeles Times/Bloomberg
(story, results)

Pennsylvania 4/10 through 4/14
Clinton 46, Obama 41

Indiana 4/10 through 4/14
Obama 40, Clinton 35

North Carolina 4/10 through 4/14
Obama 47, Clinton 34


POLL: SurveyUSA Kentucky Dems


SurveyUSA

Kentucky
Clinton 62, Obama 26


POLL: GQR (D) National Women


Greenberg Quinlan Rosner Research/
Women's Voices Women Vote Action Fund

  • "Despite historically lower levels of participation, unmarried women are nearly as energized as their married sisters. Huge majorities of each cohort describe both their likelihood of voting and their interest in this election as a “10” on a ten-point scale (76 percent of married women say they are very likely to vote, compared to 68 percent among unmarried women)"
  • "Democrats do well among women in general in this survey, but to take just one example, married women prefer a generic Democratic by a 53 - 38 percent margin (15 points), compared to a 66 - 25 percent margin among unmarried women. This represents a 26-point marriage gap on this measure."

Read the full analysis here.


POLL: The Daily Rasmussen


Rasmussen Reports

National through 4/14
Obama 50, Clinton 41
McCain 47, Obama 43... McCain 48, Clinton 41

Favorable / Unfavorable
McCain: 53 / 45
Clinton: 43 / 54
Obama: 49 / 49


POLL: The Daily Gallup


Gallup Poll

National through 4/14
Obama 51, Clinton 40
Obama 46, McCain 44... Clinton 46, McCain 44

Also
Americans Have Net-Positive View of U.S. Catholics - Video
87% Say U.S. Economy Getting Worse


Another Update on PA by Race, Gender and Education

Topics: 2008 , ARG , Barack Obama , Hillary Clinton , Quinnipiac , Trend lines

Another Pennsylvania survey from Quinnipiac University presents another opportunity to check the results broken out by race, gender and education. The subgroup numbers, like the overall results, look mostly unchanged since last week, although Obama's favorable rating dropped slightly among white men without a college degree.

As noted in previous reviews, Quinnipiac enables this analysis by (a) asking a demographic item on education, (b) interviewing very large sample sizes, including the largest yet (n=2,103 likely Democratic primary voters) this week and (c) sharing the additional tabulations with all of us. Thanks again to Quinnipiac's Doug Schwartz for the additional data.

Keep in mind that the latest survey was conducted from Wednesday to Sunday (April 9-13) so we can assume that a significant portion of the interviews were completed before news broke Friday afternoon about Barack Obama's so-called "bitter" remarks. The usual cautions are also in order about this survey being a snapshot in time with a full week to go before voting. However, note that the field period of the ARG survey released yesterday (Friday to Sunday) overlapped entirely with that of the new Quinnipiac poll. A trend in the vote preference as large as indicated by the ARG survey should have been evident in the Quinnipiac data, but Quinnipiac tells us that they see "no noticeable difference" comparing the interviews from Saturday and Sunday to those completed earlier in the week.

On to the crosstabs. The vote preference results that appear in the following show few meaningful differences within subgroups. Obama's support among African Americans increased significantly (from 75% to 86%), while he showed a small drop among college educated white women (from 46% to 41%) that was not quite large enough to attain statistical significance (college educated white women were 13% of the sample, or roughly 275 interviews this week and roughly 200 last week).

(Click on the table to pop-up a slightly larger version).

Hillary Clinton's favorable rating looks essentially unchanged since last week, with no subgroup showing a change in any category of more than 2-3 percentage points.

Finally, Barack Obama's favorable rating shows no statistically meaningful difference overall and among most subgroups, although the survey does show a significant nine-point drop (from 60% to 51%) in his favorable rating among white men with no college degree. Notice that this change brings Obama's current rating among non-college men (51% favorable, 27% unfavorable) back to more or less where it was two weeks ago (53% favorable, 29% unfavorable).


POLL: SurveyUSA Penn Dems


SurveyUSA

Pennsylvania 4/12 through 4/14
Clinton 54, Obama 40

SurveyUSA Blog Post: Is Clinton-Obama more like Rendell-Fisher? More like Specter-Hoeffel? Or more like Bush-Kerry?


POLL: Rasmussen Penn Dems


Rasmussen Reports

Pennsylvania 4/14
Clinton 50, Obama 41


POLL: Quinnipiac University Pennsylvania Dems


Quinnipiac University

Pennsylvania - 4/9 through 4/13
Clinton 50%, Obama 44% - unchanged from 4/3-4/6

From the release: "There was no noticeable difference in the matchup in polling April 12 – 13, following widespread media reports on Sen. Obama’s ‘bitter’ comments."

Update: More on results from Quinnipiac by race, education and gender here.


Bialik Asseses ARG, Teases Quinnipiac

Topics: 2008

Carl Bialik has a nice assessment of the ARG poll in Pennsylvania that includes this tease of the new Quinnipiac numbers due out tomorrow:

Other pollsters’ numbers disagree with ARG’s. Clay Richards, who runs the Quinnipiac University Polling Institute’s Pennsylvania poll, said he doesn’t expect his poll that will be published Tuesday to show much difference from the last one, which had a Clinton lead of six points. “I don’t see that much movement in Pennsylvania myself,” Mr. Richards said by phone from Harrisburg on Monday. He declined to comment specifically on his rival’s contradictory numbers.


Pennsylvania Dem Trend Sensitivity

Topics: 2008 , ARG , Barack Obama , Hillary Clinton , Susquehanna Polling , Trend lines , Zogby

1PAStandardSensitivity.png

Time for a look at the sensitivity of our trend estimators. ARG has a new Pennsylvania poll out showing a 20 point Clinton lead. But Susquehanna Polling has one completed three days earlier with a 3 point Clinton lead and Zogby has one on the same day with a 4 point Clinton lead. Did things shift that swiftly or do we have an outlier?

Our standard trend estimator is designed to resist outliers, and it manages to do so in this case (see the chart above.) With or without ARG (and with or without ARG AND the close Susquehanna poll) the trend estimates only change by 10ths of a percentage point. What does change slightly is the slope of the trend estimate between the solid line with all polls and the dashed and dotted lines without ARG and without ARG and Susquehanna. In fact, the changes are slight enough you need to squint to really see them.

It may surprise you that removing ARG makes Clinton's trend estimate go UP, when you would understandably expect it to go down. The reason is simply that she is trending down either with or without ARG. Removing ARG means that the latest poll for the trend estimate is 3 days earlier, hence higher up on the downward trend. Since ARG doesn't much affect the slope, removing it just "backs the trend up" by three days, making Clinton a tiny bit better off. The same happens in reverse for Obama-- without ARG he is a shade worse off (0.1 percentage points) because his trend is rising either way, so backing up 3 days hurts him a tiny bit. (Removing ARG and the close Susquehanna poll makes similarly modest changes to the trend estimate.)

So for our standard estimator, whether we include or exclude the latest ARG poll makes very little difference.

That is by design. At this point a single new poll that shows a big change should be regarded with caution. It MAY reflect a big shift over the weekend. But it could just as easily be a statistical fluke that will not be replicated in other new polls. Until there is more evidence one way or the other, the trend estimate is designed to not chase after a single poll far away from the other data. But if we get two or three more polls showing similar results, the trend estimator will then be convinced the shift is real, and will turn in the direction of the new data.

But what if we decided to be less cautious and more willing to respond to new polling? For that, we have an alternative estimator that is about twice as sensitive. This one will pick up new trends much more quickly, but will also be misled by a single outlier much more easily. Let's see what this more sensitive estimator thinks is going on.

2PAMoreSensitive.png

With the sensitive estimator, the ARG poll makes a HUGE difference. It shifts the difference in trends from a 4.3 point Clinton lead to a 12.6 point lead! That is really responsive. But it also demonstrates what a large difference a single poll can make when we crank up the sensitivity of the trend estimator.

What is more interesting with the sensitive estimator is that taking out ARG, we see a flattening of Obama's trend and even a tiny downturn, though also a continued decline for Clinton. If we also take out Susquehanna we find Obama continuing to rise but Clinton falling at a slower pace than without ARG alone. (You really have to squint to see the dotted line. Sorry about that.) Clinton leads by 4.2 without ARG AND without Susquehanna, by 4.3 without ARG alone.

So perhaps the sensitive estimator is showing us something new-- Obama may have flattened or even turned down a shade recently, but if so Clinton seems to have continued to decline as well. This also illustrates why we prefer our more conservative estimator. The sensitive version is just too dependent on individual polls at the end of the series. It provides a possible early hint of things to come, but is too unstable to count on. Our standard estimator may be a little slow to pick up a change of direction, but it seldom chases after random noise.

As for ARG's result, let's wait a day or two and see what other polls have to tell us and how our estimator responds.

For an animation of the Pennsylvania sensitivity analysis for a wide range of sensitivity, download this Acrobat file and use the arrow keys to control the animation speed.


POLL: PPP North Carolina Dems


Public Policy Polling (D)

North Carolina 4/12 through 4/13
Obama 54, Clinton 34


POLL: SurveyUSA Indiana Dems


SurveyUSA

Indiana 4/11 through 4/13
Clinton 55, Obama 39


Comparing Pollsters in Pennsylvania

Topics: 2008 , ARG , Barack Obama , Insider Advantage , PPP , Quinnipiac , Rasmussen , SurveyUSA , Susquehanna Polling

I know the question just about everyone following the Pennsylvania primary contest is asking today is what polls are showing regarding the impact of the "bitterness" flap involving comments made at a fundraiser by Barack Obama last week. We have two new surveys released so far today, one from ARG conducted as the "bitter" story broke over the weekend (4/11-13) and one from Susequehanna Polling and Research University completed earlier (4/6-10). We will have more clarity on this story's impact as more polls are released, but in the meantime -- thanks to Charles Franklin -- here is a chart that can help put these new results into context (click on the image to pop-up a full-size version).

The chart plots the Clinton margin (Clinton minus Obama) separately for each pollster that has released two or more Pennsylvania surveys since February 1 (except Susquehanna -- Charles ran this chart just before we received that release). We have also plotted our "standard estimate," the margin based on the standard regression trend lines that we plot in our Pennsylvania chart.

A few notes about the data, although as always, your interpretation may differ:

First, every pollster showed some decline in Clinton's margin between mid- and late March, as reflected in the black trend line which shows that margin shrinking from roughly 13 to roughly 7 points.

Second, several pollsters (SurveyUSA, PPP, Insider Advantage and ARG) have shown upticks in the Clinton margin since April 1. These findings affect the trend line by flattening out its slope. But the margins reported by the four pollsters are scattered from well below to well above the trend line, making their effect on the overall estimate less powerful than it would be if they all agreed on the level of support for each candidate.

[Update: Also notice that surveys by Quinnipiac, Strategic Vision and the last ARG showed a down tick, and Rasmussen was flat, just a day or so before the three others reported an up-tick up].

Third, the black trend line continues to show Clinton's margin declining because the regression model that generates it gives greater weight to the larger number of polls conducted earlier showing a decline. The new ARG survey is so different from other polls that, with a more sensitive estimator, the line would move quite a bit in its direction, producing an upward spike. Our more conservative estimator is pulled up by ARG, but it is designed to resist the influence of single poll that falls far from the rest. If other new polls are consistent with ARG, then the trend estimator will move sharply in that direction. But if new results look like other recent polls, then the trend will remain about where it is.

[Charles Franklin updates with much more on the sensitivity of the Pennsylvania estimates].

All of which is a long way of saying that for the moment, your judgement about where the trend is headed depends on what you make of the ARG poll.

Fourth, the Pennsylvania surveys from PPP have been something of an outlier in terms of their sheer volatility. They produced the biggest Clinton margin (by far) in mid-March (in a survey conducted entirely on March 16, on the eve of Obama's speech on race) and the one result showing a slight Obama lead on April 1. Again, only time will tell whether ARG has produced a similarly outlying trend or is the harbinger of comparable results yet to come.

Beyond that, we can only stare at the chart and speculate. So far at least, the two national tracking surveys are not showing evidence in a significant shift since Friday in Obama-Clinton vote preference. As Josh Marshall noted, however, "coverage of this story in Pennsylvania has likely been as intense as anywhere in the country." So we will have to wait and see what other Pennsylvania polls have to say.

On that note: Quinnipiac University has distributed a media advisory that will be releasing their latest survey tomorrow morning. So stay tuned.


POLL: The Daily Rasmussen


Rasmussen Reports

National
Obama 48, Clinton 44
McCain 49, Obama 42... McCain 47, Clinton 43

Favorable / Unfavorable
McCain: 54 / 43
Clinton: 46 / 51
Obama: 48 / 50

Florida
McCain 53, Obama 38... Clinton 45, McCain 44

Louisiana
Sen: Landrieu 55, Kennedy 39

North Carolina
Sen: Dole > 50, Dems < 40

Also
56% Disagree with Obama's Comments on Small Town America

UPDATE: The original post was in error. See this post for more details.


POLL: The Daily Gallup


Gallup Poll

National through 4/13
Obama 50, Clinton 40
Obama 46, McCain 44... Clinton 46, McCain 45

Also
Just Half of Americans Complain Tax Bill Is Too High - Video
U.S. Satisfaction at 15%, Lowest Since 1992
Heightened Economic Gloom Persists


POLL: Susquehanna Pennsylvania Dems


Susquehanna Polling & Research

Pennsylvania 4/6 through 4/10
Clinton 40, Obama 37


POLL: Temple Pennsylvania General Election


Temple University

Pennsylvania 3/27 through 4/9
Obama 47, McCain 40... Clinton 51, McCain 40


POLL: ARG Pennsylvania Dems


American Research Group

Pennsylvania 4/11 through 4/13
Clinton 57, Obama 37


 

MAP - US, AL, AK, AZ, AR, CA, CO, CT, DE, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY, PR