I may have jumped the gun on the race issue. At least I hope I did. The closeness of the race (2 points, maybe 3) would not indicate an underlying bigotry. This was, after all, a Democratic primary. I'd expect it from the Republicans, but not from the Democrats.
Hopefully we'll know more in the days to come, but my best guesses...
Although most of them voted on the Democratic side, enough independents (who can vote in either primary) asked for Republican ballots to vote for John McCain, and that kept Obama's overall vote total down.
The under-30 voters didn't turn out as strongly as they did in Iowa.
New Hampshire voters were fed up with the "coming coronation" of Obama, and decided to let America know that they can make up their owns minds, thank you!
And, as exit polls show, NH women went for Clinton by at least 12 points over Obama.