My take on why Obama has stalled in the polls:
The shift away from the Republicans is pronounced everywhere and few doubt that the Democrats could make big gains in both House and Senate this autumn. This is partly behind the worries about Obama: he’s trailing his party by a significant margin. However, it may be that the margin is precisely what’s giving voters pause. The threat of the kind of Republican agenda that propelled George Bush from 2002 to 2006 is, after all, much diminished. McCain, moreover, is not so bad a figure to deal with a Democratic Congress from the perspective of many independent voters, especially since Congress is pretty much reviled as well.
The choice has evolved to that between an all-Democratic government, headed by a senator whose newness is still one of the most striking things about him, and an old, familiar warhorse who irritated all the right Republicans at one point or another and has a record of bipartisan achievement. Seen in that light, the voters’ reluctance to swing behind Obama in landslide numbers is understandable.
Obama has huge liabilities.
He has never held real executive office and has been in Washington barely for a single senatorial term. He came out of nowhere to dominate the scene in ways that many Americans are still trying to process. He has been criticised as a far-left extremist, a prissy elitist, a cynical centrist and a secretly Muslim fraud. Examining this figure who is asking to be president at the tender age of 47, watching him adapt and move on the national state, is a sensible precaution. Americans are a prudently cautious lot and it speaks well of them that many are reserving final judgment.