Polling on Chris Christie

Governor Chris Christie has dominated the buzz of speculation about possible new candidates for the GOP presidential nomination. Will he or won’t he? How many times must he say “no”? (Saying “yes” once would do it.)

How does Gov. Christie look in national polling and in comparison to other GOP candidates? There is a limited amount of national polling available, just five polls in 2011 that asked for a Favorable or Unfavorable rating of Christie. Shown in the chart above, the demonstrate that his favorable rating has consistently outpaced his unfavorable, though both are dwarfed by the number of respondents who say they don’t know who he is or don’t know enough to give an evaluation. There is also consistency the levels of these ratings: favorable has remained in the 20-26% range, unfavorable in the 13-22% range, and unable to rate has been in the 50-65% range. No noticeable trends for any of these polls.

In this, Christie looks like a lot of governors who, however well known in their home states, are far less visible nationally, or even regionally. In the June NBC/Wall Street Journal poll, 37% of respondents from the Northeast were unable to recognize Christie, only 10 points less than the 46-49% in the other three regions. And an additional 21% of northeasterners rated him “neutral”, raising those without a favorable or unfavorable view to 58% even in the northeast (and 64% nationwide).

Christie’s advantage though is that his net approval has remained positive at between 3 and 9 percent more favorable than unfavorable. In that, he is better off than many potential GOP candidates.

The figure below looks at favorable and unfavorable ratings for GOP presidential candidates or would be candidates since February. Because name recognition plays such a big role at this point I plot net favorability (favorable minus unfavorable) against the percent unable to rate (either not recognizing or rating as neutral). I highlight Christie, Romney and Perry for useful comparisons.

Christie turns out to look better than any other candidates at his level of name recognition. No one with more than 50% unable to rate does as well on net-favorability as does Christie.

Romney is better known, and in the most recent polling (ABC/WP, 9/18) is enjoying a net positive rating, as in several recent polls. Gov. Perry on the other hand has not reached positive territory on net favorability in any of the four national polls currently available. His recognition rate has risen a bit but is still not dramatically different from Christie’s.

Reports, even as I write this, have Christie once more declining to enter the race. But a look at this chart certainly helps explain why there has been so much desire for him to enter. By no means is he well known or wildly popular with the national electorate. But he compares favorably with every other GOP figure that has been tested on the favorable-unfavorable measure this year.

Methodological note: These are national polls of adults or registered voters. These are not polls of Republican primary voters. The latter are highly relevant but Christie has modest representation in those polls. Further, some of the interest in him revolves around competitiveness in the fall, so these national comparisons are quite relevant to that discussion. Obviously all these candidates poll much better among GOP respondents, a topic for another day.

Has Perry Support Declined?

Some argue there has been no decline in polling support for Gov. Rick Perry among GOP primary voters. The chart above, and I, disagree. That looks like a bit of a dip at the end, from just barely over 30.1% to 27.1%.

But don’t take my word for it. Let’s check a completely independent source, RealClearPolitics.com:


The blue line is Perry. Looks to be down from about 32 to 28.4, according to RCP’s table.

So my trend estimator has taken a dip, RealClearPolitics’ moving average has also dipped.

So why then does The New York Times’ Nate Silver characterize my previous post as

One misconception is that Mr. Perry’s standing had been declining in primary polls prior to Thursday evening. This simply isn’t the case, at least not to any degree of statistical significance.

At first, I feared I had made an embarrassing mistake, but checking the arithmetic shows that the different conclusions between Silver and RCP and I have to do with the time perspective one brings to the data. And that turns out to be just a little more interesting than a mere statistical pissing match.

Silver comes to his conclusion by averaging the polls from Aug 13-Sept 6, and from Sept 7-Sept 19. Happily we both agree that RealClearPolitics.com’s list of national polls of GOP primary voters are the right polls to use, so our different conclusions don’t result from different sets of data. Silver finds the average Perry support before the first debate was 29.0 and after is 28.4 (also RCP’s current moving average.) That’s a change of just -0.6 percentage points, and we agree that is not statistically significant. (In point of fact, Silver uses a simple average, which ignores the differing sample sizes across the polls. If we correctly weight the polls to account for variations in sample size, the pre-debate average is 27.4 and the post-debate(s) average is 27.7, a gain of +0.3 and Silver would seem righter than he knew.)

So why do we differ in conclusions? Silver’s assumption is that the pre-debate polls are all homogeneous, with no time trend across them, and likewise for the post debate polls. If that were true, his approach to pre-post comparisons would be fine.

In contrast, my approach to estimating trends in polling, and the different but philosophically similar moving average approach of RealClearPolitics is that public opinion is dynamic and constantly moving. I and RealClearPolitics estimate trends that respond to these short term fluctuations in polling, rather than compare static pre-post groups. And that does lead to different conclusions about how Governor Perry has been doing recently.

Let’s look at a closeup of Perry’s polling since June 1 (there are few polls that include him before that date in any case.)

The gray line is my trend estimate based on all the polls. It is the same trend as the first chart of this post, except zoomed in to show more recent detail. The recent decline is numerically the same but looks far milder because of the different time scale, 4 months vs 30. The red lines are also trend estimates but calculated separately for the pre- and post-Perry entry data. The sharp jump after Perry enters is hard to capture instantly with any trend estimator, so the red lines provide an alternative view. As you can see, the red and gray trends nevertheless follow each other closely except right at the point Perry enters. The conclusion they offer about recent change is the same.

The critical point we see is that Perry support  was rising when he entered and his support continued to rise up to September 1. The red line shows a clear peak there, and the gray line reaches and then maintains a plateau.  The red line peak is a shade higher at 31.4%, but it falls off to 28.5% at the end, a decline of 2.9 points.  The gray line peaks at 30.1% and declines to 27.1%, a three point decline.

And there lies the difference between Silver’s analysis and mine. Perry entered the race on an upswing and continued to gain before his trend reversed direction just about September 1. Since then, he’s come down about 2.9 to 3.0 points. That isn’t a huge loss. He’s not in free fall. But he isn’t holding steady either.

What drives this are the four polls just before September 1. Two are quite high, above 35%. Another at 29% is as high as any previous poll. And one is rather low. But average them (or fit them with my trend estimate) and together they argue for a peak in Perry support. (The sample-size weighted average for the four is 31.78%, close to the peak of the red line at 31.4%.)  One could debate the two highest polls as outliers. Removing them would certainly change the trend. Sometimes outliers are indeed influential and a more conservative approach to the data would consider this but that issue wasn’t part of the difference of opinion that started this exchange since both Silver and I include these two high polls.

If we compare the last four polls before the first debate with the most recent four polls (three entirely after the 2nd debate and one that straddles the 2nd debate) we get an estimate of 27.06 (accounting for differing sample sizes), again quite close to my trend estimate of 27.1, and a decline between the two sets of four polls of 4.7 percentage points, a bit higher than my trend estimate.

My conclusion is that there has been a modest but clear decline in Perry’s support since the first debate. Whether you believe that or not depends on how you view the dynamics of polling. Accounting for short term change, as I do, clarifies the rising support for Perry before September 1 followed by an equal decline since then. If you prefer to treat the earlier polls as static and homogeneous, and likewise those after debates began, then you will agree with Silver’s conclusion that Perry is as popular with GOP voters now as he was before the debates began.

Horse races take at least two horses, so before ending let’s see Romney’s performance over the same period:

It is clear Romney has also enjoyed some dynamics, falling over 5 points but recently reversing that decline. From his low of 17.8% he has now climbed to 22.6%. During some of that time Perry’s rise was outpacing Romney’s but as of polling through September 19, the gap between Perry and Romney has closed to about 4.5 points. Perry remains the front runner.

At the end of my original post on this I suggested that the continued media focus on Gov. Perry’s debate troubles has helped mask continuing potential trouble for Gov. Romney. One reason Perry zoomed up so rapidly is that a sizable share of GOP primary voters are not satisfied with Romney and were happy to embrace a strongly conservative alternative. Perry’s problems don’t mean that lack of enthusiasm for Romney has changed. My analysis here still shows Perry in the lead and if no other strongly conservative candidate enters the race this may well remain the horse race of the year. Romney has yet to demonstrate he can win over those who were reluctant to support him four years ago even when paired against a candidate having some trouble adjusting to presidential debates.

Perry’s Lead Over Romney Falls After Debates

After two debates Texas Governor Rick Perry’s lead over Mitt Romney for the GOP nomination has fallen by a bit over 5 points. When Perry entered the race he enjoyed an immediate 15 point net bounce in his polling versus Romney. That moved Perry from 5 points behind Romney to 10 points ahead. This lead remained steady across nine polls prior to the GOP debate on September 7 at the Reagan Library sponsored by NBC and Politico. Following that debate there may have been a slight decline in Perry’s lead, but following the September 12 CNN/Tea Party Express debate in Florida, that lead clearly declined to slightly under 5 percent. That amounts to giving up 1/3 of the sharp gain after Perry entered the race, but still leaves Perry ahead of Romney and in a considerably better position than before he entered the race. After Thursday night’s third debate we will look for new polls to say if this decline continues or not.

The New York Times’ Nate Silver notes the decline (previously quite apparent here.) Silver however seems unsure of the evidence, saying “Whether Mitt Romney has gained ground on Rick Perry in the Republican primary race is questionable.” I’m unclear what is questionable about it. These are all national polls of GOP primary voters and there are 9 polls after Perry entered and before the first debate, and 7 polls after the 9/7 debate. While more polls are always desirable this is a pretty solid set of polls.

Initial media reaction to Thursday night’s debate suggests Perry again turned in a less than winning performance. So far, those negative media reactions appear to have also been the reaction of GOP voters. What remains to be seen is if the GOP’s somewhat reluctant embrace of Romney will ultimately help Perry, as Republican voters focus on a Perry-or-Romney choice. Romney had considerable trouble in 2007 and 2008 in winning over high church attendance GOP voters. Perry’s initial jump in support strongly suggests that GOP voters were not ready to embrace Romney prior to Perry’s entry. The uncertainty I think that remains is whether the problems elites see with Perry’s performance will overcome the reluctance of many GOP voters to accept Romney as the party nominee.

At the moment the focus on Perry’s claims in his book and on the campaign trail have helped divert a critique of Romney’s past weaknesses that haunted him in 2007-08. Ironically, Perry may be running interference for the criticism Romney might otherwise be suffering. And so far, there is no other credible GOP alternative.