After Clinton's win in Pennsylvania a couple of weeks ago, it looked to some like her campaign might have a chance. If you tossed in the vote in Michigan and Florida, you could make the case that although Obama was leading in delegates, Clinton was leading in popular vote. She was hoping to couple that with a big win in Indiana and a close vote in North Carolina to convince superdelegates that she was more electable.
But last night ended that hope, and may have effectively ended the campaign for Clinton. Obama scored a huge win in North Carolina. He scored a 14 point victory and extended his delegate lead. He will get at least 13 more delegates from that state than Clinton will get.
At the same time, Clinton was unable to score a big victory in Indiana. As I write this, there is only a 16,000 vote lead for Clinton out of more than a million votes cast. There are still votes to be counted, and it now looks like whoever wins will do so by less than 5,000 votes. No matter who wins, Indiana has to be considered a draw, especially in delegates (which is the only thing that really matters).
Clinton gave her "all the way to the convention" speech last night, but this has to be considered a crushing defeat for her. In fact, she has cancelled her morning appearances on the network news shows. She will be meeting with her superdelegates today.
Obama now has at least 1818 delegates to Clinton's 1669 according to CNN. That gives him a lead of around 149 delegates. He only needs 207 more delegates to reach the magic number of 2025.
For all intents and purposes, this race is now over.
UPDATE - For what it's worth, MSNBC has declared Clinton the winner in Indiana.