The killing of Osama bin Laden gave the President a minor boost in his reelection prospects. It hasn't lasted. According to Rasmussen, which to my mind is the most reliable of pollsters, because he always does "likely" voters, and doesn't skew to a fictitious sampling of Democrats much larger than their representation in the population, Obama's approval index is at -16, with 39% strong disapproval versus only 23% strong approval.
We know the White House watches the polls, and we know that they have their own internal polling. This cartoon today by the great Michael Ramirez captures how much they rely on them:
Here's my take, though: it's even worse for Obama than the polls suggest. He won election at 53%-47% over John McCain, a very weak Republican candidate at a time when the GOP brand had taken a beating under George W. Bush, and during a horrible downturn in the market that voters inevitably pinned on Bush. He will be seeking reelection presumably over a stronger Republican candidate (Rick Perry?) with the GOP brand in resurgence (Chris Christie? Paul Ryan?), and with the continuing economic malaise firmly tied to his own bad policies (tax increases, the stimulus, the deficits, over-regulation, etc.). Much of his first election success was driven by the novelty of having a black man as President; that novelty has worn off. Much of it was driven by his affecting centrism; we now know he is a dyed-in-the-wool leftist. Much of it was driven by his being "above" partisanship; we now know he is a hyper-partisan from the Chicago wards. Much of it was driven by his supposedly soaring rhetoric; we now know he is a male version of Mrs. Malaprop.
Most of all, I believe that Obama's victory was driven by overwhelming turnout by suburban women (who thought voting for Obama was the right thing to do as a sign of racial healing); by African-Americans (who voted for Obama out of a strong sense of tribe.... sorry, there's not another accurate word for it); and by young voters (who voted for Obama because it was the cool thing to do). I think suburban women now will vote against Obama because economic worries will trump racial guilt; and I think young voters will vote against Obama (at least in greater numbers than they did), because he just isn't cool anymore. Finally, I think African-Americans will voice their disappointment by quietly staying home on election day. It won't be a big shift, but it will be enough to cut a percentage point or more off his margin.
Put all these things together, and I think that a solid Republican candidate will defeat Obama handily, much like Ronald Reagan defeated Jimmy Carter in 1980. I think this is what the President's internal polling is showing, and I think you will see increasing signs of desperation from the White House as we move forward toward 2012.