Clinton victorious in Pennsylvania, projections say

Hillary Clinton snagged the win tonight in Pennsylvania's primary she had to have to stay in the race, the Associated Press, CNN, NBC, Fox, Reuters, and Bloomberg just projected.

But it's not clear yet whether she won by enough to cut into Barack Obama's lead in delegates and popular vote -- or to sway superdelegates who will likely determine the Democratic nominee.

The conventional wisdom is that Clinton needs to win by double digits to change the momentum of the nomination battle. The Pennsylvania primary was the first contest in six weeks and the biggest prize left on the calendar with 158 pledged delegates.

Heading into Pennsylvania, Obama led by about 140 delegates. In the remaining nine contests through June 3, with 408 pledged delegates, Obama is favored in four, Clinton in three, and two are toss-ups.

But for tonight, the Clinton camp is celebrating.

The mood at Clinton's victory party is jubilant. Tom Petty's "American Girl" was just pumped through the loudspeakers as news organizations began calling the primary for her. Supporters were jumping up and down, hoisting signs above their heads, hugging, and congratulating one another.

"We were outspent 3-to-1, they ran negative ads against her," Terry McAuliffe, Clinton's campaign chairman, said on MSNBC.

Clinton won, he said, because voters trust her to deal with the economy and be commander-in-chief.