Ruth Marcus has an op-ed commenting on Haley Barbour's comments on Obama, the one where he said: we know the least about him of any President. She correctly says: the point is, we don't know anyone like Obama. I'd expand that--he doesn't fit into familiar narratives. For past Presidents, we have a handy label/narrative we can apply: GWBush, frat boy cheerleader; Clinton, fat boy band leader with alcoholic stepfather; GWHBush, WASP aristo; Reagan, frat boy with alcoholic father; Carter, engineer nerd peanut farmer; etc. etc
We recognize these stereotypes/narratives don't represent the whole man; they're unfair. But I suspect partisans on both sides would agree there's a key element of truth in them. They give us a handle on the reality. With Obama the anti people are reacting as I did with Reagan (my person label for him was the "senior idiot").