The Washington Post reports the widely held perception that Mitt Romney is underperforming in swing states compared to the national poll. According to their poll, Obama leads by 2 nationally and 11 in swing states. Of course they polled swing states as an aggregate and electoral votes aren't awarded that way.
The chart above shows the average Obama lead in each swing state and how much of a change it is since 2008. So while Obama leads Romney in all swing states in their poll, he leads by an average of 4.7 points in the swing states. The move is slightly more than how much Romney has improved over McCain. So Romney is not really doing any worse in swing states. If the margin is Obama by 2, as the Washington Post has the race, the national poll has moved 5.1 points, more than the 3.8 swing state change.
Obama overperformed in swing states in 2008. Romney will have to improve in swing states by more than the 7.1 points McCain lost by.