I still hold to the opinion expressed below. Undecided voters are going to go with their guts, and, in anxious times like these, their guts will be crying out for relief.
McCain's selection of Palin yesterday was the exact opposite of an offer of relief. If Obama doesn't overreact, and the most recent evidence of keeping it together was the successful convention, and the polls reflect my opinion, the only suspense left will be whether McCain will keep gambling with his decisions.
It's possible that Palin has the potential to be a great President. There's simply not nearly enough evidence of that potential, nor enough time before election day to generate new and convincing evidence.
Before yesterday, McCain's most forceful argument, righteously rebutted by Obama in his acceptance speech, was that in his decisions McCain puts "Country First." There's no way now for McCain to avoid admitting that actually his campaign needs to put "Winning First." It's not a senseless argument. After all, every President, except Ford, had to win the election first. And, there's nothing essentially worse about reminding voters it's up to them as opposed to offering oneself as a leader whom one has to take or leave as is. But, Obama's already done a good job of grabbing that humble populist turf. Essentially, McCain has conceded that Obama is qualified to be President.
McCain is admitting he's a gambler, and he's asking us to give him chips to keep going.