Washington (CNN) - Sen. Arlen Specter, D-Pennsylvania, was forced Monday to defend his vote against Elena Kagan to be the solicitor general, cast last year when he was still a Republican.
President Obama, who is backing Specter over Rep. Joe Sestak in the Democratic Senate primary, nominated Kagan to replace Justice John Paul Stevens on the Supreme Court.
"I voted against her for Solicitor General because she wouldn't answer basic questions about her standards for handling that job," Specter said in a statement. "It is a distinctly different position than that of a Supreme Court Justice."
Kagan was confirmed by the Senate in March 2009 and Specter abandoned the Republican Party to become a Democrat one month later.
Kagan's nomination adds another twist to this very competitive primary and Specter emphasized that his vote against her to be solicitor doesn't mean he will oppose her nomination to the Court.
"I have an open mind about her nomination and hope she will address important questions related to her position on matters such as executive power, warrantless wiretapping, a woman's right to choose, voting rights and congressional power," Specter said.
But Sestak, who said he supports Kagan's nomination, took the opportunity to criticize Specter for his willingness now to reconsider his support for the solicitor to join the Court.
"I expect Senator Specter may backtrack from his earlier vote on Ms. Kagan this week in order to help himself in the upcoming primary election," Sestak said in a statement. "[B]ut the people of Pennsylvania have no way of knowing where he will stand after May 18."