Forget the debate about whether Obama is "American enough." He's that great American archetype, the audacious salesman with an eye on the main chance. Nothing in his utterly orthodox left-wing record ever suggested he was a transformationally unifying figure, but he sold himself as that to the audience he needed in the Democratic primaries. Nothing in his record suggests he's a sensible centrist, but he's going to sell himself as one to the audience he needs in the general election, whatever contortions it takes. In his current TV ad, he touts his support for welfare reform when he actually opposed it.
Obama is calculating shrewdly now -- just as shrewdly as back when he was attacking calculation. His left-wing base won't abandon him, and all the dewy-eyed new voters attracted by him will stay that way, so long as he continues to look and sound good. His task is to win over general-election voters in a center-right country who value hardheadedness and practicality in their presidents.
Barack Obama doesn't need to be a messiah figure. He needn't even be particularly admirable. In a poisonous year for Republicans, he just needs to be a minimally acceptable Democrat, and so minimally acceptable he aims to be. But we're a long way from Des Moines.