Category: US Politics

With less than two weeks to go, it’s high time for another presidential election thread – especially now that I’ve been inspired to put pen to paper by a fascinating article from Peter Kellner of YouGov, a British polling firm which has been sticking its oar into the American campaign.

The broad picture painted by the mountain of opinion polling is that a handy lead to Barack Obama disappeared after the first debate, and that to the extent that he is still favourite it is because he maintains slender leads in key swing states. According to RealClearPolitics, Mitt Romney now has a 0.5% lead on aggregated national polling after trailing by 0.2% two days ago. However, Nate Silver of FiveThirtyEight gives Obama a 70.3% chance of victory by virtue of state polling which shows, among many other things, an adjusted 1.9% lead to Obama in the likely crucible of the election, Ohio.

Until now, my favourite explanation for Obama’s stronger performance on electoral college projections has been that America’s decaying industrial “rust belt” is over-represented in the list of key states, which includes Wisconsin, Michigan and Pennsylvania together with Ohio. Romney’s image as a rapacious capitalist has by all accounts been especially damaging to him in these areas, owing to their long history of mass lay-offs and economic decline. This was illustrated when the General Motors bailout emerged yesterday in the context of what was supposed to be a debate about foreign policy, with Romney again haunted by his assertion from 2008 that the government should, as the New York Times subeditors helpfully paraphrased it, “let Detroit go bankrupt”. However, Kellner points to an intriguing alternative explanation involving polling methodology, with encouraging implications for Obama.

In the United States as in Australia, polling generally involves contacting random samples of respondents, the composition of which differs entirely from one poll to the next. However, the alternative approach, known as panel surveying, is to call back on the same set of respondents to determine how many are changing their minds. As Nate Silver observes, there are good reasons why this method is not generally favoured: the fact of being surveyed on multiple occasions may influence the way respondents behave, and a biased sample will produce consistently biased results, rather than random variation in the direction of errors from one poll to the next. The virtue of the approach is that it provides a more stable footing for evaluating changes over time, which is especially useful in the event of a significant shift such as that which the polls appeared to detect after the first debate.

As Kellner explains, YouGov fortuitously conducted just such a survey on a vast scale both before and after the debate. Whereas the RealClearPolitics aggregate saw a 4.3% lead to Obama on September 29 turn into a 1.3% lead to Romney by October 13, the panel survey found next to no change, with the small number of respondents switching from Obama to Romney matched by an equal share going the other way. What did emerge though was a crucial distinction in response rates from one survey to the next. Whereas the first survey elicited 33,000 responses, YouGov was only able to get 25,000 to complete the survey after the debate. This included 80% of those who indicated support for Romney the first time, against only 74% of the Obama supporters. That meant the raw numbers became immensely more favourable for Romney, and remained so after the data was weighted in the normal fashion according to demographics (by age, gender, region and race).

However, when weighting was further done according to party identification – so that responses from those identifying as Republican, Democrat or independent carried equal weight from one poll to the next – the effect of the differential response rates washed out, along with all but sliver of the swing to Romney. Responses are weighted in this fashion by YouGov as well as Rasmussen, but not by most other American pollsters. The argument against this approach (which, amusingly enough, has most often been heard from liberal critics of Rasmussen, which is renowned for its Republican lean) goes that party identification can change sharply in response to specific events, and that weighting for it negates their impact on voting intention. However, YouGov’s evident failure to find large numbers of individuals who changed their tune after the debate (allowing for the previously noted qualification that panel respondents may be shy about admitting they have changed their minds) suggests that, on this occasion at least, party identification weighting might have produced more meaningful results.

Nate Silver was moved to hypothesise that a lack of such weighting might cause polls to exaggerate bounces which occur in response to focusing events such as party conventions and clear debate victories. This is not to say that the poll shift to Romney isn’t meaningful, as the surge of enthusiasm which made Republicans more forthcoming when pollsters came calling could equally translate into higher turnout, with very real consequences for the outcome. However, Kellner offers a compelling counter-argument: that as the campaign intensifies with the approach of polling day, the enthusiasm gap and its attendant advantage to Romney will diminish. This may well be reflected in Obama’s lead in the swing states, where campaigning is already quite intense enough.

With the Democratic convention under way, and two months minus one day to go until the big day, matters American are looming sufficiently large that I’m starting up a dedicated thread to accommodate them. At this stage of the race, all indications are that Barack Obama has a clear but not insurmountable lead. Premier US psephoblogger Nate Silver of FiveThirtyEight calculates a 74.8% chance of an Obama victory, which has widened over the past week owing to a sub-par convention bounce for Mitt Romney (Clint Eastwood, we salute you). With 270 Electoral College votes required for victory, averaged poll results give Obama leads of over 5% in states accounting for 221 votes, and Romney leads accounting for 182. Piggies in the middle:

It should be noted that these figures capture Romney in his convention bounce, and conventional wisdom (no pun intended) tells us they should now be set to bounce the other way.

… discuss the mid-terms on this thread.

Best of luck to Barack Obama as well. However, the truly momentous and inspirational aspect of yesterday’s result was my almost perfect prediction of it, as published in Crikey last Friday. Obama has carried the erstwhile red states of Iowa, New Mexico, Colorado, Virginia, Ohio, Nevada, Florida and Indiana, with two states coming down to the wire: Missouri, where McCain leads by 5868 votes (0.2 per cent), and North Carolina, where Obama leads by 14,053 (0.4 per cent). I tipped Obama to gain all of these states and no more. I gather late counting of declaration votes is unlikely to change any leads, so it appears those 0.2 per cent of voters in Missouri have stood between me and my moment of destiny. Better luck next time, I guess. To those who tipped McCain victories or record-breaking Obama blowouts and find themselves wondering what my secret is, one simple piece of advice: believe the polls (or Intrade if you prefer – it will usually tell much the same story). They may not be perfect, but they will outperform your own “informed conjecture” well over 50 per cent of the time, no matter how clever you think you are.

If the last two states play out as expected, the final result will be 364 electoral votes for Obama against 174 for McCain, pending one complication: Nebraska, which along with solidly Democratic Maine divides its college votes by congressional district. Two of the three districts have stayed Republican, but in a third Obama trails by just 569 votes, and thus stands a chance to make it 365-173. In any event, the joint winners of the informal Poll Bludger tipping contest (thanks to Juliem for conducting this) will be David Walsh and Ron, who I gather will win a tie-breaker ahead of fellow 364 Club members Grog and Peter Fuller.

Finally, our good friends at UMR Research have published qualitative polling on Australians’ attitudes to the President-elect. Those who harbour an unfashionable element of cynicism about the great man might want to keep a sick bag handy.

Or possibly one day, depending on what time zone you’re in. This will in any case be the final thread for presidential fat-chewing purposes prior to the live blogging of the count, which will begin an hour or two before the first states close their polls. Firstly we have the latest polling aggregate figures, in which McCain has (at the time of writing) taken the lead in Indiana and Missouri and narrowed the gap to various degrees in Ohio, Florida, Virginia and Pennsylvania, while losing ground in Colorado, New Mexico and New Hampshire.

Not sure how illuminating this is, but the following map shows the swing in each state as indicated by Electoral-Vote’s poll averages. White indicates either no change from 2004 or a swing to the Republicans, the latter only applying to Massachusetts where John Kerry presumably garnered a handsome home-state vote. The deepest shade of blue indicates a swing of over 20 per cent. Swing is measured by comparing the vote gap between Republican and Democrats.

This chart indicates how polling in various states has shifted since October 13, as measured by my own polling aggregates. John McCain’s furious campaigning in Pennsylvania has yielded a 7.7 per cent narrowing, which while highly impressive is still nowhere near enough. He has also gained ground in Florida (Obama’s lead is down 4.3 per cent to 3.1 per cent), North Carolina (4.1 per cent to 0.5 per cent), Virginia (3.5 per cent to 5.6 per cent) and Missouri (from 2.3 per cent behind to 0.7 per cent ahead). Barack Obama has extended his lead in New Mexico (up 5.7 per cent to 12.8 per cent), Washington (up 3.8 per cent to 15.7 per cent) and Minnesota (up 3.1 per cent to 9.9 per cent). Ignore Maine, where there have only been a few polls.

Finally, many thanks to reader Viggo Pedersen for compiling this list of poll closing times in Australian Eastern Daylight Time.

With less than a week ago to the big day, the polls are showing only a fractional narrowing in Barack Obama’s formidable lead. Such narrowing has been enough to move North Carolina to the John McCain column on my polling aggregates while making Indiana line-ball, but Obama is retaining his tight grip on the rust-belt swing states while increasing his lead in Florida. For some local colour, our good friends at UMR Research have produced another poll on Australian views of the contest. It finds Obama’s lead over McCain among Australians has widened still further in the past month, from 66-13 to 72-9.

Since our previous episode we’ve had individual polls from red states Georgia and Montana showing Barack Obama narrowly in front, so they’re now included in the polling aggregates. However, John McCain leads in both due to the overall polling picture from the past few weeks. The other remarkable development has been an Obama blowout in Ohio, underscoring a picture of Democratic strength in the rust belt states.

So who’s going to win then? The polls of course leave little room for doubt. However, there are a couple of items of conventional wisdom floating around which suggest they might not be telling the full story, one way or another.

• The Bradley effect. A compelling paper by Dan Hopkins of Harvard University examines the popular notion that polls overrate the performance of black candidates in biracial contests due to white voters’ reluctance to appear illiberal when interrogated by pollsters. Hopkins finds the effect was a serious factor into the 1980s, most famously when black Democratic candidate Tom Bradley failed to win the Californian gubernatorial election in 1982, but has ceased to be so. Pew Research charts a corresponding decline in the number of respondents willing to admit they would not vote for a black candidate, from 16 per cent in 1984 to 6 per cent. Hopkins notes a very sudden decline in the Bradley effect (he prefers the “Wilder effect”, after Virginia Governor Douglas Wilder) “at about the time that welfare reform silenced one critical, racialized issue”.

• The reverse Bradley effect. Strictly speaking, a “reverse Bradley effect” would involve voters telling pollsters they were voting for McCain or were undecided when they were in fact set on Obama, which is plainly not on the cards. Far more likely is that turnout of black voters is being underestimated in pollsters’ determinations of “likely voters”, which in many cases go on whether they voted last time rather than what they say they will do this time. Whatever methods are being used to account for the certainty of higher black turnout, I’m pretty confident they are overly conservative. When a pollster is required to explain inaccuracy after the event, “I was going on past experience” makes for a more professional sounding excuse than “I made a wrong guess”. I haven’t studied this systematically, but the one example I have looked at has proved to be an eyebrow-raiser: the most recent SurveyUSA poll of Pennsylvania has 10 per cent of black voters among its overall sample, whereas this paper from the Joint Center for Political and Economic Studies tells us it was 13 per cent in 2004. Nate Silver at FiveThirtyEight provides support for this and related impressions in taking to task pollsters who have gaps of 4 to 6 per cent between results for “registered” and “likely” voters.

• The late Republican surge. I recently heard it said that Republican candidates tend to come home strong in the last week or two of campaigning. Remembering how much of Bill Clinton’s lead vanished shortly before the 1992 election, I thought this sounded plausible and went burrowing through the archives for evidence. The following chart plots the last 15 days of polling at presidential elections from 1992 onwards, day 15 being the election result. I have used composites of polling obtained from Real Clear Politics for 2000 and 2004; Gallup tracking polls for 1996; and a list of various pollsters’ results I found in the New York Times for 1992.

The case of 1996 stands out, but this might well point to a general inaccuracy in the Gallup series I was using rather than a late surge to Bob Dole (unfortunately I could only locate one poll from the final week). Beyond that, the chart provides pretty thin gruel if you’re in the market for a McCain comeback in the last 10 days. The 1992 Bush recovery was less dramatic than I remembered it once I removed Gallup from the equation, which exasperatingly shifted from “registered” to “likely” voters in the final week, eliminating much of Bill Clinton’s lead at a stroke. If anything the trends from 2000 and 2004 point the other way.

• Front-runner decline. The aforementioned paper on the Wilder/Bradley effect by Dan Hopkins informs us that polls “typically overstate support for front-runners”, which is demonstrated in the scatter plots under “Figure 3” (see right at the back). These suggest a candidate like McCain who is on about 42 per cent is probably being underestimated by as much as 2 per cent, while a candidate like Obama on 50 per cent is probably being represented accurately – unless he’s black, in which case he will suffer a Bradley effect of a bit over 1 per cent.

• Advertising. The Washington Post informs us that the cashed-up Obama campaign is fielding “as many as seven commercials for every one aired by Republican Sen. John McCain”.

My guess is that point one will be comfortably countered by point two; point three is worth little if anything; point four might help McCain close the gap by 2 per cent, but some of this gloss should be taken off after accounting for point five. In sum, there seems little reason not to take the polls more-or-less at face value. That being so, my final prediction is that Obama will win every state where my polling aggregates currently have him ahead except North Dakota, where the result is derived from two small sample polls, one from an agency of little repute. The margin in Florida is narrow enough that front-runner decline might be expected to account for it, but I find it hard to believe Obama would fail to carry so marginal a state when he’s up by eight points nationally. That makes it 375 electoral votes for Obama and 163 for McCain.