But Clinton is still about 100 delegates behind, and the Democrats' proportional representation rules make it impossible for her to close the gap in the remaining primaries. Her only plausible path to the nomination is to win a majority of super-delegates (party and public officials) and, perhaps, to reverse the party's decision disqualifying the Michigan and Florida delegations -- i.e., overruling the voters in one case and changing the rules after the game has been played in the other.

This might pass muster if the national polls show an unambiguous and substantial move toward Clinton. Otherwise, in more likely and ambiguous circumstances, a Clinton nomination will seem illegitimate to many who have been swooning over Obama and streaming into polling booths because he alone offers hope.