From NBC's Mark Murray
As we predicted in First Thoughts, Joe Sestak's campaign is seizing on Arlen Specter's vote against Elena Kagan in 2009, when the Senate was confirming her to be U.S. solicitor general. Specter voted against her before his switch to the Democratic Party.
"I applaud President Obama's selection of Elena Kagan to serve as our next Supreme Court Justice. The President's background as a constitutional law professor served him well in selecting Justice Sotomayor, and I believe it has again in this case," Sestak said in a statement.
But he added: "My opponent, Sen. Specter, has already made his views about the president's nominee clear by voting against her confirmation to be Solicitor General, even as seven of his fellow Republicans approved her nomination. I expect Sen. Specter may backtrack from his earlier vote on Ms. Kagan this week in order to help himself in the upcoming primary election, but the people of Pennsylvania have no way of knowing where he will stand after May 18.
The Specter-Sestak Democratic Senate primary in Pennsylvania takes place next week, on May 18.