January 31, 2008
Super Tuesday Polling at a Glance
(Note: We will constantly be updating these charts to reflect the most recent poll data.)
No time for commentary this morning, so here is an explanation.
It is ironic and annoying that the most important date on the primary schedule is also the date with the fewest polls per state. Just as the campaigns are struggling to run 22 simultaneous campaigns, so pollsters and the media have invested little in comprehensive polling of the Super Tuesday states. Even large states such as New York and California have fewer than 10 polls since January 1, far fewer than we saw last week in Florida for example. As a result, we have many states with no data at all, preventing a comprehensive overview of the prospects for Tuesday. Even where we do have polls, we lack enough to consistently estimate the trend with data taken since Iowa. Where we can estimate trends, we've done so on the "regular" state pages at Pollster.com. You should go there for the best trend estimates we can manage with so little data.
The charts here are a way of seeing the entire set of Super Tuesday states (where we have polling) at a glance.
Rather than plot the usual trends with so few data points, each poll is a point and the darker the point the more recent the poll. The points are also scaled in size to be proportional to the number of delegates at stake in the state.
Instead of a trend estimate, this plot highlights the median of all post-Iowa polling in the state. The shading of points will then let your eye tell you whether there is a visible trend around that median. Be your own data analyst!
When more states become available, they'll be added to updated charts. If a state is missing, we don't have polling for it. (If you think we've missed a state with polling data, let us know!)
By Charles Franklin on January 31, 2008 9:06 AM | Permalink
Comments
these charts are Tufte-esq. good work.
Great charts!!!
Thanks!
The polls FlyOnThewall pointed out are now included in the charts on the front page (where we'll be posting all the updates.)
Charles
Nice chart... But the numbered axis is misleading, and somewhat incorrect. Since you go to the trouble of labeling the "Obama ahead" and "Clinton ahead" sides the negative signs on the Obama side are misleading. He can't be ahead by a negative margin. For accuracy both sides should have positive numbers.
Holy Tufte, Batman!
Great chart but it think shades of gray/black are hard for older eyes like mine to distinguish. How about color?
charts above are great, although harder to estimate # of delegates each predicted to win. these aren't all-or-none contests (or maybe a few are?). what about 3-D bar charts, where depth axis is history. each state could get its own pattern
Charles, nice cutting to the chase and graphics. Now if we just had a way of weighting these polls by their prior accuracy.
Try using color instead of shades of grey... not easy to determine (though I realize some are color blind). Cool colors in the past warm colors for the most recent.
Thanks to all for the suggestions. In the interest of stability I'm not going to make changes at this point, but will keep these in mind or future plots.
Some people seem not to understand what is there now, so adding color, for example, or different colors or symbols for primary vs caucus or PR vs Winner take all (all of which have been suggested here or at Political Arithmetik) seems to be pushing what casual readers can absorb. It is an interesting challenge that the more information represented in a chart the more room for misunderstanding.
Charles
Nice chart- thanks. Any chance of getting the presidential approval chart updated? It's only showing polls before 12/09
Thanks
I find it disturbing that for a website poll not to include the most searched candidate on the internet speaks volumes on the inaccuracy of this poll. You know of whom I speak. I wont be visiting again.
For B. Belcher,
Just to set the record straight, Ron Paul is included in ALL of our state pages and in our national pages and has been since the beginning. I can include Ron Paul, but I can't seem to make his supporters notice that we have included him. This particular chart is obviously about the two candidates in each party with the highest poll support, which is why he is omitted here.
Charles
good mmmm.
Charles,
Thanks for the easily legible charts. Here are a few polls out this morning:
Rasmussen: In Massachusetts (43-37) and California (43-40) Clinton's lead is shrinking. They'll release the Dems in Illinois at midday.
WNEC has a badly-flawed, incredibly out-of-date survey released today that shows Clinton with a 43-15 Massachusetts lead. (Taken 1/20-26; undersampled men, minorities, youth; margin is 8 points.)
PPP yesterday had the NY race at 45-33.
In Alabama, the Capital Survey Research Center (the teachers' union) shows Obama surging to a 40-35 lead on the strength of growing black support.
And in Minnesota, a new Public Radio/Humphrey Institute poll finds Clinton's lead down to 7, at 40-33.
Posted on January 31, 2008 9:29 AM