Michael Crowley, my colleague at the New Republic, argues that Obama might have benefited from more debates with John McCain. I tend to agree, although for somewhat different reasons. Namely this one -- McCain has a tendency to come across as sneering and contemptuous of Obama:
When McCain is speaking to a television camera, and Obama is on the other side of the country, this behavior probably does not do much to harm public perception of him (the disastrous Green Background Speech perhaps being something of an exception). McCain can be seen as attacking OBAMA! (TM), the brand, rather than Barack Obama, the man. Besides that, McCain is (rightly) viewed as the underdog in this race, which can make this attitude easier to swallow.
When the two men are on the same soundstage, however, McCain does not have the same buffer -- an attack will seem far more personal. Contemptuousness, condescension -- these things are unappealing qualities in a potential President, as Obama himself ought to know:
Likewise, George W. Bush's sneering performance at the Miami debate on September 30, 2004 was nearly a disaster for him; John Kerry closed his polling deficit from about 8 points to 2 nearly overnight:
The first President Bush also had some problems with this. Note his sarcastic disposition toward Bill Clinton in this vintage footage, and particularly in his response that begins about 8:05 into the clip.
Even this famous moment did not produce any bounce for the Dukakis-Bentsen ticket in the polls:
It can, of course, reasonably be argued that this contrast in tone and demeanor will not take more than three debates to establish. There is still some chance, in fact, that if McCain turns in a sufficiently unattractive performance during this year's first debate at the University of Mississippi, that may be all that is needed to tip the momentum of the election.
But in general, when an opponent is attacking you -- and McCain is attacking Obama now -- you'd rather make him do it when he's standing right next to you.