One thing to keep in mind about tonight's overwhelming victory: If Obama ends up winning the nomination, I suspect the GOP will look at the Clintons' aggressive assault against him in South Carolina, and some of the racial innuendo their surrogates used, and wonder if these tactics backfired and if they'd be risky in the general election.
Now, obviously the GOP doesn't expect to win a lot of black votes in the general either way. But Obama also won about 25 percent of the white vote tonight, after polls showed him as low as 10 percent coming in. That, too, could be the result of an anti-Clinton backlash. At the very least, I'm sure it raised some eyebrows at the RNC...
--Noam Scheiber