Monday, October 15, 2012

Was it the Debate?

Kevin Drum notices something interesting in the polling averages:
According to both Pollster and Real Clear Politics, Mitt Romney began his big surge well before last week's debate. In the ten days before the debate, Pollster shows Romney gaining 2.4 points and RCP shows Romney gaining 1.8 points.
Okay, I'm going to look at all of this in some detail, but just to skip to the point: I'll tentatively agree with Drum, but a lot depends on how the averages are being compiled, which gets into technical issues that go beyond my expertise.

But before I get to that, Drum asks "Anyone have any good guesses about what happened during that last week of September?" My guess is that the answer is: nothing. Which means that instead of news that was one-sided in Barack Obama's favor, which it had been since the Democratic convention started, the news resumed being balanced, thus finally deflating a bounce that was artificially prolonged by September 11 (which likely plays for Obama, bin Laden killer), an initial rally effect from the Libya attack, the Romney response to the Libya attack, and 47%. During periods of one-sided information flows, we would expect undecided voters to temporarily park with the candidate getting good news or be less likely to park with the one getting bad news; we would also expect likely voter screens to pick up more of those who support the favored candidate and fewer of those who support the disadvantaged one -- even if no one actually makes new decisions.So if you ask a marginal Romney voter in early September who she's going to vote for and all she's heard lately is that Romney is in trouble, she might say that she's undecided. So what might be happening in the ten days or so before the debate is that the news environment goes back to even, and all that temporary stuff washes out, revealing a 2-3 point lead for Obama rather than the 4-5 point "bounce" version.

As for whether that happened? Looking closer at Pollster (and if you don't care about the details, skip down to the last paragraph for my guess at an overall story that fits)...

The "HuffPoll model" version has Obama's lead peaking on September 23-24 at 48.4 to 44.2 (with Obama's support going up to 48.5 on September 25), and then falling steadily and rapidly after that. The debate was on October 3; Obama's lead was down to 2.2% on October 2, 1.7% on October 3, 0.9% on October 4, and 0.4% on October 5, reaching just 0.3% on October 7 before heading back up -- it's not at 0.7%. But remember that Pollster is drawing trend lines, not simply averaging the polls on a particular day. So it's possible, I think and if I'm understanding the way the model works correctly, that a real sudden drop might get smoothed out by the computer to look as if it happened over time (however, and again if I understand correctly, that would not happen with the RCP average that Drum also noted).

Ready for it to get more complicated?

Switch off Pollster's model, and go to their "create your own" trend line, and now Obama's lead peaks at 4.0%...but now that peak is September 17-20! The lead, by that measure, erodes a bit over the next week, but then falls quickly, and in fact that version now has Romney in the lead by 0.8%.

But that's with "moderate" smoothing. That is, the trend line is set to not overreact to small fluctuations in the polls, which most of the time are picking up nothing but random variation. Use Pollster's "more smoothing" option, for that matter, and the whole Romney October surge never happened; the trend line treats it as random movement and smooths it over, and Obama still has the same lead of about two and a half points that he's had all year.

Assuming that's not correct, what if we use Pollster's "less smoothing" option? Call that one the Andrew Sullivan option -- it's designed to (over?) react to any hint of change in the polls. That one has Obama 49.0, Romney 45.3 on October 1, with the Romney surge coming just after that. Or, to be more technical, Romney starts moving forward after September 26, while Obama doesn't start falling until October 2.

Now, remember, even a little "smoothing" of the trend line is going to make the original lead smaller, as the computer thinks that some of that lead was just random movement to Obama. Which might be true! On the other hand, it might not be. And, to tell the truth, I don't know whether the settings they're giving us are even capable of picking up an overnight 5 points swing even if it happened, or if it would automatically distribute it over several days.

I'd like to see Mark Blumenthal (or Simon Jackman) comment on all of that, but overall I think that there's at least something to what Drum said: the debate happened in the context of a falling Obama lead. On the other hand, Sam Wang, who spends a lot more time looking at the polls than I do, thinks that it was really an immediate 5.5% post-debate bounce...I just don't see that in the Pollster numbers.

My guess -- and it's really only a guess, but it fits pretty well with the numbers and with what we general know about voters, is this: Obama had a small lead before the conventions. During the conventions, Obama added to that lead, giving him about a 2-3 point edge, mostly by getting straying or low-information likely Obama voters to shift to him...and he also had a temporary bounce which then stayed in place for a couple of weeks thanks to a series of campaign and world events. The debate gave Romney a 3 point or so bounce, bringing him to a very slim lead, which is now receding. If nothing else happened, we would eventually see Obama's lead settle back at 2-3 points -- if the debate bounce was purely temporary -- or about 1 point, in the relatively unlikely event that Romney really did permanently grab some straying or low information likely Romney voters. But of course events and campaigning keep happening, so it's always very difficult to know for sure.

14 comments:

  1. It's clear that Obama's advantage was receding in the week leading up to the Denver debate. I think it's safe to assume that, even with a merely solid (non-dominant) debate performance, Obama's lead would still have reverted to about 2 or 3 points post-Denver, reflecting both the fundamentals of the race and the long-term polling average.

    Instead, because of the poor debate performance, we had what looked like a precipitous drop, from around O+5 to R+1. But that might really be a combination of three things: (1) Obama's post-DNC, post-47% bounce receding; (2) the debate increasing R enthusiasm and decreasing D enthusiasm; and (3) people actually changing their minds due to the debate.

    I guess the question for the Obama campaign is, how much is attributable to factor #2, since that's the only one that can be expected to disappear by itself with time.

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  2. Obama's biggest mistake was that he had no plan B. Romney's tack to the center was predictable, and the "zingers" warning just a decoy. What Obama failed to do was immediately to call Romney out on his reversals by saying (in some fashion or other), "My goodness, who are you and what have you done with the real Mitt Romney?" He could have followed that up with, "Here's what he's been saying to his supporters for the last 18 months, and here's what he's saying now. Are we all supposed to ignore everything he's been saying as just electioneering? How can you trust someone like that?" He could have then lasered in on his own record as in line with nearly everything he's talked about since he was a candidated in 2008. Voters -- low information or junkies like me -- appreciate consistency and steadfastness in their politicians. How else would George W. Bush have gotten reelected? "At least you know where I stand." That went a long way against, "I was for the war before I was against it." Waffles are for breakfast, not for politics.

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    1. Yes, but it's important to note that Romney's policy proposals have not actually changed. It's only his description of them and of their likely consequences that has changed.

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  3. Fascinating stuff. I have some kind of related questions:

    I remember you making the case that Romney's on-the-record support of far-right positions such as the Ryan budget was going cost him politically. Do you still see that happening? Do you anticipate it happening more dramatically in the next few weeks, or are voter perceptions "locked in" now? Do you think that Romney has successfully telegraphed a "moderate enough" brand to voters, so as to dilute the Dem attacks on his far-right positions?

    So maybe The Debate didn't matter as much in the long haul... or it mattered in a way that was more complicated and nuanced than "Romney swung the election overnight." That doesn't mean that it's going to be very easy for any of us partisans on either side to watch The Second Debate tomorrow night.

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  4. the other thing is all these polls say 2 or 3% possible variations which may be what we see. Polling is not an exact scientist and if would then swing this way or that with no real change ever having happened. It keeps people reading the papers, watching the news which suits the media.

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  5. In the last few weeks (since the debate), we've seen a string of encouraging economic reports. Why aren't these reports boosting Obama in the polls? Are people that swayed by one 90-minute debate?

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    1. No, they're swayed by the intense media reaction to the debate performances.

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  6. I think it makes more sense to point out that Romney's comments in the debate exposed large weaknesses in Obama's big myth - that he is well-informed, intelligent, and successful. I'll never forget the moment where Romney says that he never saw a tax break for taking business overseas in 25 years as a businessman/counsultant. Obama had no capacity to react and was exposed as an empty suit. The new Gallup poll shows that a realignment has taken place - especially among female voters.

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    1. Sorry, but this comment section is not for hack writers to vomit up pre-fabbed right-wing BS talking points.

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    2. So after the experience of almost four years of the Obama presidency, it took only a few Romney comments in a debate to convince voters that the President is an empty suit. Gee, John, why did the Republicans wait so long to demonstrate this apparently simple fact?

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    3. Let me get this straight. The President is an "empty suit" because he's not intimately familiar with tax loop holes the rich use to cheat the system? Considering Romney was wrong about this -- i.e. there IS a tax break for taking business overseas -- you may have fingered the wrong empty suit.

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  7. what you are not factoring in is that most of the pollsters started switching over from Registered voter models that favor democrats to likely voter models about a month out from the election. Which just happened to coincide with the debate.

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  8. If Obama takes Ohio and Nevada he wins.

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  9. JB: you can't really use ANY smoothing to get into this. Smoothing necessarily involves taking in data points from before and after the date in question. It really isn't a good idea if you're looking for inversion points.

    For any fellow Dems that would like to get the wrist-slitting done early, I just looked at Nate Silver's data on debate effects, and it's not good. Now, Silver focuses on whether the effect of debate 1 is correlated with the effect of debate 2, finds little if any correlation there (with the obvious "7 data points!" caveat).

    What I did was a few things. (HUGE SMALL DATA CAVEAT!!!!!!!!!)
    1) correlated the pre-debate 1 polls, post-debate 1 polls, pre-D2 and post D-2 polls with the final election results. Coeffs: .79, .87, .92, .89. In other words, as it gets later in the campaign, the polls were more accurate. No real surprise there, but it should be pointed out.
    2) Looked at whether the polls moved in the "right" direction or not after the first debate. That is, if Kerry was down 5.4 points, and only ended up losing by 2.5, then he was "too low" pre-debate 1. Did Kerry's share go up? Yes. 8 for 8. In every year, the first debate shift was in the correct direction. In 3 of the 8 years, it OVERcorrected (so, Kerry gains 3 points, but his pre-debate estimate was only low by 2.9 points, so he's one of them). In other words: the debates seem to move the race towards where it is "supposed" to be. In EVERY case, the polls after the first debate are closer to the final result than those before it.
    3) Did the same thing for the second debate. There's nothing like it. These are already pretty close to the final numbers. Only in 3 years do the polls move in the correct direction, and only in 1 year do they do so without overshooting.

    So, IF Obama is down now (and polling suggests he is), this quick-and-dirty, could-never-be-published analysis suggests that the fat lady has already sung.

    I've been in a bad mood lately, and I'm not helping things much!

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