Lot of good stuff here:

Hillary Clinton won big victories Tuesday night in Ohio, Texas and Rhode Island. But she’s now even further behind in the race for the Democratic nomination. How could that be? Math. It’s relentless.

To beat Barack Obama among pledged delegates, Clinton now needs even bigger margins in the 12 remaining primaries than she needed when I ran the numbers on Monday—an average of 23 points, which is more than double what she received in Ohio.

Superdelegates won’t help Clinton if she cannot erase Obama’s lead among pledged delegates, which now stands at roughly 134. Caucus results from Texas aren’t complete, but Clinton will probably net about 10 delegates out of March 4. That’s 10 down, 134 to go. Good luck.

I’ve asked several prominent uncommitted superdelegates if there’s any chance they would reverse the will of Democratic voters. They all say no. It would shatter young people and destroy the party.

Clinton’s only hope lies in the popular vote—a yardstick on which she now trails Obama by about 600,000 votes. Should she end the primary season in June with a lead in popular votes, she could get a hearing from uncommitted superdelegates for all the other arguments that she would make a stronger nominee (wins the big states, etc.). If she loses both the pledged delegate count and the popular vote, no argument will cause the superdelegates to disenfranchise millions of Democratic voters. It will be over.

Emphasis mine.