Today's Polls: Obama's Bounce in Context

29.08.2008

Barack Obama presently has an 8-point lead in the Gallup tracking poll, and a 4-point lead in the Rasmussen tracking poll. These are pretty numbers for Democrats to look at, but since the polls were conducted in the middle of the Democratic convention, they require a bit of a haircut.

In fact, our model is designed to tell us exactly how much that penalty should be. These polls consist of interviews that were conducted on Tuesday, Wednesday and Thursday -- so the median date of interviewing was Wednesday, corresponding with the third day of the Demcoratic convention. Our historial study of convention bounces tells us that, on the third day of the convention, the candidate will be experiencing an average bounce of about 3.5 points.

So what we quite literally do is to subtract those 3.5 points from each of these polls -- meaning that Obama's 8-point lead in Gallup is equivalent to a non-convention lead of 4-5 points, and his 4-point lead in Rasmussen amounts to a virtual dead heat. Furthermore, the model expects that Obama's convention bounce should grow over the next couple of days, peaking at about 6 points in polls released over the weekend. So, he'll need to gain a little bit more ground to keep pace. My guess is that Obama will gain that ground, and probably will have some room to spare, but until we actually get a look at those numbers, we should probably regard this as a fairly ordinary convention bounce.

Please keep the convention bounce in mind when looking at the Super Tracker over the next couple of weeks. You'll see that there are going to be some fairly big difference between the red trendline -- representing our estimate of what would happen if the election were held today -- and the orange projection line -- representing our best estimate of what will happen in November. There is little doubt that Obama would win an election held today, perhaps in a relative blow-out, but so far, the organge projection line remains about where it had been before.

We also have a handful of state polls to look at:

For the most part, I'm going to let the state numbers speak for themselves until we've cleared some distance from the convention bounce period. The one interesting result is probably in Florida, where Mason-Dixon has Obama ahead by one point, perhaps reflecting the presence of Joe Biden on the ticket. Florida is a state where we expected Biden to play well. It's also a state, frankly, where I'd expect Sarah Palin to play poorly, since I think seniors will probably be her worst demographic. Since Mason-Dixon has generally had a slight GOP-leaning house effect, this poll needs to be taken pretty seriously.

--Nate Silver

Posted: Friday, August 29, 2008 9:32 PM with 8 comment(s)

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tomeg said:

Translated: no bounce. Obama and Biden are toast. McCain/Palin should win in a landslide in the popular vote, and 370- 195. In other words, a wipe out. No point in continuing the race, the outcome is decided. No Obama, no Biden. No Democratic Presidency this year or for 30 years at least to come. Congress may follow. Liberalism is dead, moribund, extinct. Forever. War. War. War. We're finally getting the point. Only another Great War will suffice. Death to all Muslims and Mongols. Death forever. God be praised! Come quickly Jesus, come quickly, vanquish the enemies of the Lord. The time is nigh for the apocalypse. May it come swiftly.

August 29, 2008 11:18 PM

jgoffman said:

will the convention bounce be helped by the 38 million+ viewers of the convention.

August 30, 2008 1:30 AM

roidubouloi said:

Uhh, you're not reading tomeg.

August 30, 2008 2:14 AM

Mack2 said:

Tomeg wrote. That doesn't make him right. At the present time it looks like quite a bounce. But it may yet be going up since the polls still don't reflect all of the Democratic convention, including above all the last day with Obama's speech.

And then we have next week and the Republican convention. The bounce from that may be even greater -- or it may not.

Political scientists who make forecasts often look at the early September polls (esp. Gallup, if they're using historical baselines as well) as their first serious baseline for making forecasts (perhaps along with other things such as economic indicators).

But with the party conventions both being so late this year (they've been trending later in recent elections), the first polls in Sept. will be right in the middle of the Republican convention. So probably about September 15 things will "settle" and we'll have a good idea where things stand.

August 30, 2008 6:46 AM

lsernoff said:

This brilliant analyst is resolutely sticking to his long-held conviction: this election will be another squeaker.

Obama will fundamentally hold the Democratic base that Gore and Kerry had. Will he add to it? I doubt it? Every student and African-American he adds is likely to be balanced by someone who doesn't like his record (or lack thereof), the cut of his jib, or, unfortunately, his pigmentation.

McCain will fundamentally hold the Republican base that Bush had. The Palin choice will help with some of these people and McCain's reputation as a foe of pork barrel politics will help with others. Without "the surge" McCain would be a dead man walking. The success of the surge makes McCain look like a prescient prophet to the party base.

The irony, in my view, is that the Dems could have won in a walk if they had chosen to run a moderate Clinton --that is Bill, not Hillary-- campaign. Instead, they are going again with an unabashedly liberal, populist image. That hasn't won them an election since 1948. Remember, even JFK and LBJ ran as moderates, not liberals, as did Carter and Bill Clinton.

August 30, 2008 9:57 AM

Please forgive my intemperate comment(s) yesterday. That right wing Xian evangelicals were thrilled by Palin incited a temporary, utterly irrational loss of perspective. Their millennial obsession scares the s**t out of me, frankly. Also, the speculation that Rove might have had a hand in the choice was more than my poor campaign weary nerves could bear. I'm feeling sane again this morning (I think).

August 30, 2008 10:16 AM

I think we can all agree that Bill Clinton would have won this election handily. I think Hillary Clinton would have lost. Edwards, as we now know, would have been blown away. Biden or Richardon? Maybe, maybe not. I think the Dems are in the best position they could have been in with the candidates who were running, Myself, i would have preferred FDR.

Someone was written of Obama that "he is the luckiest man alive." As long as they do the job of framing McCain as "too old and feeble," "out of touch with the economic problems faced by Americans," "more George Bush," Obama's luck will hold.

The whole purpose of "the surge" was to suppress violence, and hence bad news, long enough to get the Republicans past this election without actually doing anything to resolve the mess in Iraq. In that sense, it has been a "success." But, "It's the economy, stupid!"

August 30, 2008 10:26 AM

Eos said:

lsernoff:

I think you are exactly right. It is going to be a close election because the Dem nominating process draws from the left-most elements in the party, who also happen to be way overrepresented here on TNR and in the blogosphere generally.

August 30, 2008 10:28 AM