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Re: Dueling Gallups

Topics: 2008 , ABC/Washington Post , Barack Obama , CBS/New York Times , Divergent Polls , Gallup , Gary Langer , George Bush , Hillary Clinton , John McCain , National Journal , USA Today , USAToday Gallup

A quick follow-up on my post last night about the conflicting results from Gallup on the Democratic presidential race as measured by two different national surveys: The latest USA Today/Gallup survey and the entirely separate Gallup Daily tracking. I exchanged email with Gallup's Frank Newport and can clarify two issues.

First, Newport promises further analysis on the difference between the two surveys, perhaps later this afternoon. We will link when available.

Second, the two Gallup surveys differed slightly in the the populations that were asked the primary vote preference question (which means that I assumed wrong in a comment I posted in the previous entry). The USA Today/Gallup poll reports Democratic presidential preference of all adult Democratic identifiers and "leaners" (those that initially identify as Democrats but say on a follow-up question that they "lean" Democratic). It does not screen for registration or vote intent.

As explained by Gallup's Jeff Jones in a post here three weeks ago, the Gallup Daily tracking screens further for adult partisans who also say they have voted or intend to participate in the Democratic primary or caucus in their state. They include:

Republicans or Republican-leaning independents who say they are extremely, very or somewhat likely to vote in their state's primary or caucus when it is held.

Democrats or Democratic-leaning independents who say they are extremely, very or somewhat likely to vote in their state's primary or caucus when it is held.

We [also] make provisions for those residing in states that have already held their primary caucus - those who indicate they have already voted are considered extremely likely to vote, and those who did not vote in their state's primary or caucus would be excluded from the base.

However, Newport adds that the different screen "would not by any means in and of itself account for the differences in the results between the two polls." Presumably, their upcoming analysis will elaborate.

Third, with the help of Gallup releases sent to my National Journal colleagues, I can report on the questions that preceded vote preference on the USA Today/Gallup survey:

First, we have some questions about the election for president, which will be held in November; that is, in November 2008.

1A. How much thought have you given to the upcoming election for president -- quite a lot, or only a little?

2. Do you approve or disapprove of the way George W. Bush is handling his job as president?

3. Next, we'd like to get your overall opinion of some people in the news. As I read each name, please say if you have a favorable or unfavorable opinion of these people -- or if you have never heard of them. How about --

[ITEMS A-C RANDOM ORDER, THEN ITEM D ASKED, THEN ITEMS E-G RANDOM ORDER]?

A. Hillary Clinton
B. John McCain
C. Barack Obama
[Note: E-G were omitted from the release]

4. (Asked of Republicans and independents who lean to the Republican Party) Next, I'm going to read a list of people who are running in the Republican primary for president. After I read all the names, please tell me which of those candidates you would be most likely to support for the Republican nomination for president in 2008, or if you would support someone else. [ROTATED: Former Arkansas Governor, Mike Huckabee; Arizona Senator, John McCain; Texas Congressman, Ron Paul; former ambassador, Alan Keyes]

5. (Asked of Republicans and independents who lean to the Republican Party) Which comes closer to your view about Mike Huckabee’s campaign for the Republican nomination for president-- [ROTATED: He should drop out of the race, (or) he should continue his campaign]?

6. (Asked of Democrats and independents who lean to the Democratic Party) Next, I'm going to read a list of people are running in the Democratic primary for president. After I read all the names, please tell me which of those candidates you would be most likely to support for the Democratic nomination for president in 2008, or if you would support someone else. [ROTATED: New York Senator, Hillary Clinton; Former Alaska Senator, Mike Gravel; Illinois Senator, Barack Obama].

ABC News polling director Gary Langer blogged on the conflicting national results, and he points out that "question order always is a possible culprit, but it doesn't usually make for differences like these." True, though it would be useful to know what questions precede the vote preference on the Gallup Daily tracker.

Langer also concludes with this bit of advice worth repeating about the four recent national polls (including one from CBS/New York Times showing Obama ahead by 16 points and one by AP/IPSOS showing Obama with a nominal 3 point lead):

For the moment, with the cause of these differing estimates up in the air, when considering the two national polls that show Obama ahead it would be prudent also to keep in mind the two that show the race essentially tied.

 

Comments
erik:

Interesting, I would luv to know the business/methodological logic of why Gallup used too different screeners for these polls...they must have had an inkling that contradictory results would appear, and now have to scramble to explain the differences.

Instead, for consistency sake, they could have used the more rigorous screener for their USA Today/Gallup poll - unless it was a question of cost, or that USA Today wanted to have a broader sample than the daily tracking poll.

I think they should have seen this coming and have been prepared right away to answer why the differences in results -it was foreseable if the screeners for each poll are so different.

Other than that, the results suggest in this light that the relatively pro-Obama information environment is having the effect of persuading the moderately attentive democrats, rather than die-hard, motivated, high awareness voters...

which is totally consistent with models of public opinion like Zaller's

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Davis:

I think they're too worried about the inconsistency. This seemed like as good of an explanation as you need, to me:

http://infogiant.wordpress.com/2008/02/26/different-polls-different-answers-the-elevator-theory/

____________________

Davis:

I think Gallup is too worried about their credentials. It's just very volatile right now. This seemed as good an explanation as any:

http://infogiant.wordpress.com/2008/02/26/different-polls-different-answers-the-elevator-theory/

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s.b.:

Today gallup has them tied 46% each, done Feb 23-25. So has Obama lost 16% in the 2 day difference of these polls or was there something very fishy about the screen for the Gallup USA today poll?

And who asks for that screen?

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joshua bradshaw:

is it possible that maybe he just had an absolutely huge day on the 21 which is included in the Gallup/USA Today but not in the tracking as it was taken out. Does anyone know the numbers from the gallup tracking that included the 21st. Or perhaps is there hight number of undecided did they push the undecided voters harder to make a choice in the USAToday/Gallup then the tracking.
just some thoughts

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Newport adds that the different screen "would not by any means in and of itself account for the differences in the results between the two polls."

Perhaps not all the difference, but I could see it accounting for enough difference to make the reaminder not significant. Obama has consistently done better among non-Dems voting in Dem primaries and caucuses than Clinton (53-37 so far), who has outperformed him among self-identified Democrats (50-44 so far). Removing a big chunk of those non-Dems that support Obama would surely change the outcome.

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Patrick:

These polls, as well as the outcomes of contests thus far in "open" states just further shows how completely arbitraray and unfair our primary season is. The vast, vast majority of voters are either Repbublican or Democrat. In many states, Republicans can vote in the Democratic primary or caucus. In other states, they can't. Hillary has consistently done better than Obama among registered Democrats, i.e. the people who will actually vote for the Democrat in the national election. Obama's margin of victory has often been because of Republicans (and Independents) who hate Hillary, but will vote for McCain and NOT Obama in the general election. If Huckabee had continued to do better against McCain, those Republicans wouldn't be voting for Obama in the open primaries; they'd be voting for McCain. So what you have is the Democratic candidate preferred by most registered Democrats going down because of what is happening on the Republican side! How is that fair? Last time I checked, the President of the United States was a FEDERAL office. So why is the nominating process for this federal office so completely and arbitrarily different (e.g. primary vs. caucus; "open" vs. "closed"; early states vs. later states; disenfranchised delegates (FL & MI), etc) from state to state???

____________________

New SUSA Ohio poll - Clinton up by 6, down 3 from the last SUSA poll. Considering Rasmussen shows a Clinton lead of 5 and PPP shows 4, expect a desperately negative Hillary in tonight's debate. Otherwise, these numbers will continue to drift towards Obama, and a narrow win in Ohio will leave the Clinton campaign limping with litle to look forward to.

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Davido:


Thanks xstyker. Looks like more bad news for Hillary. This is eerily similar to Wisconsin, no?

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Dewreyew:

PATRICK -

If anything, this shows the equality in our primary system. Just because your candidate got toasted, doesn't mean the system is unfair. I agree there are some things that should be changed (the super delegate influence for example) but overall, this isn't a name recognition contest. And beleive me, that is the main reason Obama didn't wrap this up on Super Tuesday.

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Anonymous:

"The vast, vast majority of voters are either Repbublican or Democrat."

They're are a lot of us independents, and we're the one's who are the crucial vote come November. Obama has huge support from independents, where Hillary has very little. Open primaries are the way to go.

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dan in nyc:

I disagree that the two surveys "differed slightly in the the populations that were asked the primary vote preference question."

At this point, more than half the states, representing much more than half the population, have voted. Democrats (and leaners) in those states who did not vote in their primary or caucus must be a sizable group that is included in the USA Today poll but not in the daily tracking poll.

And this group, having no voting history to report, would be much more likely to now prefer the candidate who won their state or whom they perceive to be leading nationally.

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Keith Pickering:

The favorability question immediately precedes the candidate-preference question, that that's a big deal because it gets Dems to thinking about McCain. And beating McCain. And Obama wins on that issue, hence Obama's numbers go up.

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