Neither, really, IMO. I've been expecting Obama to win re-election since before he won his first presidential election, and long before we knew who the candidates were going to be on the Republican side this year (Sarah Palin wasn't even on the national stage yet). The only time my expectation wavered somewhat was earlier this year when the economy seemed poised to maybe get much worse, which if it happened, could give some Republican (almost doesn't matter which Republican) an opening. But even then, I still thought it was pretty likely he'd be re-elected.

The fact that the Republican nominee is going to be someone who couldn't possibly get the Republican nomination (but got it anyway, because nobody else could either) is, I suppose, helpful, but it'd take a really extraordinary Republican candidate to beat Obama IMO. Only Obama, by stumbling in some really giant unexpected ways, can really defeat himself. I don't expect that to happen, though it's not impossible.