Analysis by Alan Fram in the Wash Times:
The two candidates' problems start with the economy, which members of both parties agreed is the country's top issue. Neither man got even half the votes of his party's voters who worried most about the economy.
Compounding their problems: McCain conceded months ago that the economy was not his strong point, while Obama has run weakest with Democratic voters who say they've been hurt by the troubled economy, a growing group.
FWIW, RealClearPolitics has Obama over McCain in most polls, though not by a lot and they were all done before the primary season wrapped up. More here.