A somewhat contrarian view:
I really can't imagine John McCain
not attending the debate tomorrow. Although it's hard to know exactly
how the spectacle would play out -- Obama fielding questions from Jim
Lehrer by himself? -- as I opined last night, I think Americans would largely not excuse McCain for failing to show up. SurveyUSA
polling data now shows that 74 percent of Americans think there should
be some sort of debate tomorrow night (though many think the subject
should be the economy rather than foreign affairs). The considerable
majority of people who oppose a debate are Republicans; 73 percent of
indepenent voters want one, as do 77 percent of moderates.
Perhaps, however, rather than trying to postpone the debate, McCain is instead seeking to increase its importance.
Surely the drama of the past 30 hours has made it an even more
captivating event, probably leading to increased viewership. Moreover,
with the subject matter likely to be expanded to include the economy,
and the candidates having had less time to prepare, the entire exercise
becomes less predictable, with gaffes more likely to occur, but also
the potential for "clutch" performances.
So perhaps instead of gambling two polling points on the debate -- the average magnitude of the shift in opinion
following one of these things, McCain would instead like to gamble
four. A two-point swing probably would not be enough to put McCain
ahead (though it would be close); a four-point swing probably would.
The
downside, of course, is that if McCain has a bad night tomorrow, he
might do enough damage to effectively end the campaign. If Obama were
to pull, say, 7 points ahead, with some structural advantages in the
electoral college and what will be a strong turnout operation, I don't
think McCain would have better than about a 1-in-6 chance of pulling
the election out.
--Nate Silver