I haven’t followed the polls in the US presidential race in any detail – there are dozens of polls every day and I could never hope to do half as good as job as Mark Blumenthal over at Pollster.com, with just a couple of days to go however, I thought it worth having a look to se whether it really is all over. With the polls consistently showing Obama ahead, can McCain still win? Let’s have a look at the possibilities.

1) The late swing. The most famous surprise result of a Presidental election was Harry Truman who was able to pose the next day with newspapers that had gone to print assuming his inevitable defeat and hailing his opponant’s victory. What happened then was that Gallup finished polling too early and, in the gap between the end of opinion polling and the actual election opinion swung to Truman. We will have polls up until the day itself so unlike in 1948 we would know. Could it happen?

It is obviously a logical possibility, however strong an Obama lead the polls show, it is only public opinion now, it could change by Tuesday. Since McCain’s convention bounce receeded Obama’s lead has been pretty solid and there is no obvious sign of it. The last slice of data in Zogby’s rolling tracker showed a shift to McCain…but there is no obvious pattern in other national match-up polls.

Besides, even it if did happen, it might be too late for McCain. Projection sites like Electoral Vote and Five Thirty Eight have Obama with a solid lead in states collectively worth almost enough electoral votes to win, in the next tranche of states, those leaning towards Obama, the ones McCain would have to get hold of to prevent Obama winning, five have early voting. In Florida a third of the total number of votes cast in 2004 have already been cast, in North Carolina, Colorado and Nevada over half of the total number of votes cast in 2008 have already been cast. If there was some event that suddenly swung public opinion to McCain in these key states, unless it was a major swing it would be too late, people have already voted for Obama.

2) So if it is unlikely the polls will change in time, what if they are wrong? There are lots of ways they could be. First up is the Bradley effect. This is commonly named after Tom Bradley, but refers to the apparant way that polling in a contest between a black and a white candidate in the USA used to underestimate support for the white candidate, presumably a social desirability bias in the answers because people are worried they may been seen as racist if they declare they are voting against the black candidate. There is some debate about whether this happened at all in US polls in the first place, but there is plenty of evidence of polls in recent years which accurately predicted elections between a black and white candidate. If there was a Bradley effect, it seems to have gone. The only way it could suddenly come back, I suppose, is if there are stronger social pressures in a Presidential race, but I can’t see it.

3) Shy McCain vote. Leaving aside the race question, could the undecideds split in favour of McCain. Indeed might there be a shy McCain vote in the way polls underestimated the Conservatives in this country in the 1990s? The answer is probably not – looking back to 1992 here, ICM found in the aftermath that the don’t knows were disproportionately people who had voted Conservative in 1987. In the USA Mark Blumenthal and Charles Franklin have got hold of a huge chunk of data on undecided voters from Financial Dynamics to analyse. When the don’t knows are pushed for which way they are leaning, they break for Obama. When Franklin analysed the demographics of those who refused to even say how they were leaning, looking at their race, party id and so on, his prediction is they are a pretty even break, in fact, if anything they’ll lean slightly to Obama.

4) Faulty Turnout Model. In the UK pollsters tend to base turnout projections on how likely people say they are to vote. In the USA turnout projections are more complex and factor in whether people have voted in the past (and sometimes various other factors as well). Early voting and current polls suggest a higher level of voting than normal in US elections. Could this help McCain? Probably not, as if pollsters are underestimating turnout it is likely to be black and/or poor voters coming out for Obama who are being understated. It may not make any difference at all: Gallup are producing parallel numbers, ones based on their traditional US turnout model, and ones based on a turnout model we are used to in this country based only on how likely people say they are to vote. In the latest figures Obama has an identical 10 point lead on both measures.

5) Weighting. Tracking how pollsters in the US are dealing with weighting is a bigger task than I can do here. Pollsters use a wide variety of weights by party ID, or in many cases none at all. Whereas in the UK demographic weightings are much the same between pollsters, in the US there is some variety because some target models of likely or registered voters, rather than the demographic make up of the whole US. We do see pollsters with different proportions of African-Americans in their samples for example. The sheer variation in the way US pollsters do things is why I suspect this is not disguising a McCain lead: with such variation, it is unlikely everybody’s method has wrong. Equally, having a black candidate is new and probably having increased turnout is new, so it is reasonable to ask whether polls can cope with these developments. There has not, however, been a sudden massive change in US demographics.

Those are the most likely reasons why McCain could still win, and I don’t think any of them work. If anything, I’m expecting a bigger Obama victory than the polls indicate. Of course, when polls do get it wrong it is normally something that we haven’t predicted and it’s perfectly possible that something completely different will come out of the woodwork. If miraculously the polls are wrong and McCain wins on Tuesday there would be one hell of a post-mortem about why the polls got it wrong, but really, I’m not expecting it.


22 Responses to “Can McCain still win?”

  1. One has to stick one’s neck out sometimes, and I work on a “most likely” basis. Not an average of the range, but the most likely result.

    I always believed Major would win in 1992, except had doubts about getting an overall majority when some polls showing 7-8% Labour leads appeared 9 days before polling.

    Short of the technical possibility, I do not believe McCain can win this election.

  2. As I’ve said elsewhere, I’ve not seen any polls that put McCain ahead for a while, and for him to win he needs to mop up nearly all the undecideds and get them in the right places. Apparently Obama is doing very well in most swing states, significantly better than in national opinion polls. It won’t quite be a landslide, but barring something unexpected I think we know who’ll be the next president.

  3. 51% to 47%

  4. I think so and I think he will.

  5. Of course if the voters think he is lying about his aunt things may change.

  6. ToryDave – based on what?

    Wolf – that’s my first point, in several of the really key states a a very substantial chunk of voters (in some cases more than half) have already voted. Even if they change their minds, they can’t go back and change their votes.

  7. I am pretty sure the Democrats only have to gain Ohio, (and hold everything else from 2004).
    I read in the Economist that they have a branch set up in all 88 counties in Ohio this time, compared to just 16 in 2004. Not sure what this all means in terms of organisation, and obviously no very little detail, but it sounds like they are better prepared, and I have not heard much to back up a counter effect beneath the radar.

  8. counter Republican effort.

  9. I think if you any of you put a bet on McCain winning the election you will win a substantial amount – I stand by prediction over the past months that Obama will not win the election !

    I personally think that both Obama and McCain are unsavioury and neither would do well in the UK – but that’s American politics and you ain’t gonna see Obama as president – not this time round anyway !

    I put my very accurate predictions in the past on the line here !!

  10. McCain is staking everything on winning Pennsylvania, but both polls yesterday still put Obama 7% ahead there. If indeed McCain fails to win there, Obama only needs to win Iowa (pretty much certain), New Mexico and Colorado (which look very nearly certain). He also seems to be quite a way ahead in Nevada. If he does win these states the results in Ohio & the other “toss-ups” wouldn’t matter. As it is however he looks in good shape in Florida & Virginia too.

    If Obama wins will Mike Richardson please stop calling himself the Oracle? :)

  11. I don’t believe McCain can win because Ohio is an almost certain Democrat gain, and I’m assuming they hold everything else.
    I don’t see why Pennsylvania should come off for the Republicans when it stayed with the Democrats in 2000 and 2004.
    I expect a pretty close result, but Obama is going to win.

  12. Just to nit-pick slightly Joe, there was a poll yesterday that put McCain 2% ahead in Ohio, but 1) there was also one which put Obama 6% ahead and 2) it has been the only poll for some weeks which has put McCain ahead there. But I wouldn’t quite say almost certain for a Democrat gain, though still very likely. As I say, if Obama wins the 3 states mentioned above, the Ohio result wouldn’t even matter provided he holds Pennsylvania. Will check the last-minute polls today for any further developments. McCain will clearly treasure Michael Howard’s endorsement yesterday……

  13. A lot of poll results are out today. Very little indeed to encourage McCain. He has probably pulled level in North Carolina, and has narrowed the gap slightly in Florida (3 polls have identical figures there), but Obama’s lead remains solid in Nevada, Pennsylvania (several polls none of which has Obama less than 6% ahead) and Virginia, and worse still for McCain Ohio, where Obama is shown as about 4-5% ahead on average. Even Montana shows a fractional Obama lead though that is a Democrat partisan poll. No sign in any of this of any meaningful GOP comeback, not at any rate one which will deliver the White House to them. The one oddity is a Democrat lead reduced to 3% in Minnesota, but that’s a Survey USA poll and they do tend to come up with very odd results in both directions.

  14. If Ohio is too close to call then that would indicate something happening beneath the radar,
    but I basically stick to what I said, that it is a Democrat gain by about 4 points.

    I have a hunch they won’t take Florida, or some of these outlyers like Virginia and North Carolina, but they don’t need to.
    Organisation seems to be an issue aswell.
    McCain will be hoping that the polls have consistently over-estimated Obama, and turnout will not match his poll figures. I strongly suggest that hope is in vain.

  15. I take it as a pretty bad sign for McCain if he is campaigning in Indiana the day before the poll.
    This has been a Republican stronghold, and remained so in 1992 and 1996 (although reduced).
    This was the result in 2004 –

    Popular vote 1,479,438 969,011
    Percentage 59.94 39.26

    I’m surprised they have hopes in Pennsylvania, against the trend.

    Still, it’s not clear from where I am whether Obama is offering pushing much in specific policy, although I presume there is some manifesto or document, but the change slogan appears to be more catchy than I’d given credit.

    John McCain didn’t appear to seize the moment on the economic and banking crisis, and the election may have turned on that.

  16. To be clear, Indiana 2004
    Popular vote
    Rep 1,479,438
    Dem 969,011
    Percentage Rep 59.94 to Dem 39.26

  17. The biggest surprise in McCain’s schedule yesterday was his visit to Tennessee. That state is clearly safe for him in this election & it seems to me a very odd last-minute waste of his time.

    Joe is quite right about Indiana. It’s awful news for the GOP that they should be in serious trouble there at such a late stage. Not at all clear that they will hold it.

    As I write this it now looks extremely close in Ohio, Florida, North Carolina & Missouri, with I think Obama slight favourite in the first 2 & McCain if anything in the other 2. But a virtual dead heat. Not so in Virginia, Nevada, Colorado or Iowa where Obama’s lead seems too consistent for him to lose, nor in Pennsylvania where again the polls have moved a bit but not enough for McCain. It would be surprising if Obama failed to pick up the odd toss-up state outside of these, such as Indiana, N.Dakota, Montana and even Georgia where early voting returns are said to favour Obama.

  18. Is the momentum truly stupendous then?

  19. oh yah. :)

  20. “If Obama wins will Mike Richardson please stop calling himself the Oracle?”

    To be fair to Mike, I think that name was originally attributed to him by someone else. Whether it was in jest or a serious compliment I’m not sure. :)

  21. Can McCain still Win?

    No…..

    Peter.

  22. It is looking quite unlikely now ;)