She lost hard in North Carolina, and barely held on to win Indiana. Hillary Clinton just doesn't have enough straws left to clutch. The best (or worst) she can hope to do the rest of the way is bloody Barack Obama enough to make him lose in the fall, allowing her to come back in 2012.
In fact, Obama basically clinched the nomination with his string of 11 straight primary and caucus wins in February, many by wipe-out margins - giving him a lead in elected delegates that Clinton couldn't hope to close, especially given the nutty proportional-representation rules that govern the Democratic Party.
Do the math. Last night's results leave him with a lead among elected delegates of 150 or so, and among all delegates of around 130.
Only a handful of states are left to vote, with a combined total of about 230 delegates. She'll probably win West Virginia, Kentucky and Puerto Rico - and lose Oregon, North Dakota, and Montana. She most likely could pick up a net 10 delegates, leaving him with a lead of at least 130 (110, counting in superdelegates).
If Hillary manages to get Florida and Michigan seated (which she won't), she'll net another 47 delegates. So Obama, worst case, will have a lead of at least 60 delegates. Most likely, it'll be more than 100.
Senate Majority Leader Harry Reid, House Speaker Nancy Pelosi and Democratic Chairman Howard Dean have all made it clear that they expect superdelegates to decide who to support within (in Reid's words) "days, not weeks" after the last ballots are cast on June 3.
In that environment, Obama - who'll be only about 100 delegates short of a majority - will be an irresistible choice. Few superdelegates will want to risk civil war by overruling the verdict of the voters - and almost all will want to climb aboard the victory bandwagon so as not to get shut out of the White House for four (or eight) years.
In the past few months, Obama has closed Clinton's lead among superdelegates from 60 to 20. The trend will accelerate after popular voting ends; he'll probably pass the 2,025 threshold in the first two weeks of June.
Clinton may stay in, hoping to can seat Florida and Michigan. But she won't win there, either.
The Credentials Committee, which will make the key report, consists of three votes for each state or territory. The remaining contests will leave him with, at worst, a 10-state lead. Howard Dean names 25 committee members, but she can't prosper unless he stacks them all for her - and, if anything, he'll go the other way.