The Superdelegate Conundrum

So if Rep. James Clyburn (D-SC), who comes close to calling former President Clinton a racist, who believes that African Americans think that the Clintons "are committed to doing everything they possibly can to damage Obama to a point that he could never win," who says these things in multiple venues (Reuters, the New York Times).... still won't endorse and still won't call for Clinton to drop out, should it surprise us that other superdelegates are even more shy?