I would be astonished if Obama lost. I suppose I'd chalk it up to idiocy. But, it's fine; I think McCain would be okay.
GWB and a general repudiation of a party driving the bus into a ditch. Obama ran a nearly flawless campaign, but as a Jackie Robinson figure, he had to. Sarah Palin was the nail in the independent coffin.
Sarah Palin killed McCain. Her main purpose was to steal Hillary voters and it failed because she proved to be totally incompetent and ignorant. 80% of Hillary supporters (women) in Pennsylvania voting for Obama should tell you everything you need to know.
McCain put far too much stock in the love he used to get from the media and spent too much time trying to pander to that crowd when he should have been using his forward momentum from locking up the nomination so early to solidify the base and get his message out while Hillary and Obama were still going at it. He failed to utilize Republican star power and went into attack mode too late, looking desperate as a result. Say what you will about Palin, but it would have been an even bigger blowout without her. The base was apathetic towards him until her selection.
I liked McCain, 4 years ago, when he was a bipartisan maverick. It seemed that he changed into Bush III over the last 4 years. He also scared me when he said he didn't know much about economics. Then, he really turned me when he could only talk about Obama and sling mud. His only answer to the issues was to avoid it and do Ayers robocalls.
^ and that's not to take anything away from Obama's campaign. It certainly didn't help that the Dems finally ran a charismatic candidate.
What killed it for the republican party was McCain. He was the least electable from the primaries. Obama is pretty hard to beat if he stays towards the center and stands by his "change" campaign. Americans have the attention span of a gnat, so if Obama doesn't pull this country from its recession, he will doom the next democratic president.