Super-delegates probably will decide the nomination
Marty Lederman writes on Balkinization: According to the Obama campaign, he won 845 of the 1671 pledged delegates last night, to Senator Clinton's 836. This appears to be roughly consistent, give or take a few delegates, with others' estimates, as well -- see here and here. When added to his previous 63-48 lead, that would give Obama a 908 to 884 lead in pledged delegates. (The Obama campaign's estimate of his own pick-ups might even be a bit short -- he might have won four more delegates than he assumed in California, according to this calculation. There are also seven more delegates to be chosen from Democrats abroad who voted yesterday.)
Only 1428 pledged delegates are still to be chosen in the remaining primaries and caucuses. Thus, in order to enter the convention with a majority (2025 delegates), Senator Obama would need to win 1117 of those remaining delegates, or over 78 percent. Senator Clinton would need to win 1141 delegates, or 80 percent. Obviously, neither of the candidates is going to secure anywhere close to a majority before the August convention. It is more likely that each will end up with between 1500 and 1700 pledged delegates, i.e., at least 300 delegates short of what they need to win.
Therefore, the Democratic nomination will be decided by the 796 "superdelegates." They include all Democratic members of the Congress, Democratic governors, various other elected officials, and the members of the Democratic National Committee.
Just over 300 of the superdelegates have already announced who they intend to support, and Senator Clinton is ahead by about 90 such delegates in most counts. (Here is one list of those who have already announced their endorsement.) Most of those delegates presumably will stick by their announcements, but they are not bound to do so. -- Balkinization: It's a Tie -- Enter the Superdelegates