On the one hand, there is the view that Barack Obama is a radical; his so-called agenda is nothing but campaign noise, as are all politicians' agendas. The person he really is can be glimpsed in the totality of his associations and personal history. This Mr. Nobody did not get to where he is today on the strength of any supposedly brilliant policy positions. He is a creature of the extreme disaffected Left, an avatar of black rage and white guilt, a rallying point for fifth-columnists, a purveyor of jejune internationalism, an advocate of wealth redistribution, and a leading figure in the ethno-bolshevist front. That is his base of support, and there's no denying it.

On the other hand, it could be posited that Obama is an outsider who perfected the art of fitting in. His entry point into America was a specific subculture, and he befriended people and told the things that made him fit in there. Now he's out for a bigger role in a bigger group, and again he's telling people things they want to hear. He doesn't have a lot of deeply held beliefs. When he becomes president, he'll have debts to pay, but he won't be ideological beyond what he needs to be re-elected, i.e. he won't disappoint his base too much while avoiding being frightening to the center vote. Expect a few small projects to please his wife, but on most issues he'll be a reactive pragmatic.

One might say that McCain has deeply held beliefs on some issues and in normal mode doesn't care what the world thinks about them. His conviction can be sufficient to get together coalitions in the club that is the Senate, but his problem is that he has to run against much of the base of his party. If he pleases them, he comes over as insincere (because he lacks Obama's ability to believe what he is saying when he tells people what they want to hear); if he talks straight, he risks losing them. Probably he has ruined his credibility by trying to please the base.

So, at the current stage, we have an opportunist packaging himself as a reformer running against a stubborn man who has damaged his own credibility and shown that he clings to every possible straw when drowning.