It was only a matter of time. In striking back at the Sestak camp for its ad on Arlen Specter's Republican past, Specter's camp brings up Eric Massa -- another ex-Navy congressman who endorsed Sestak shortly before resigning, after a male aide accused him of sexual harassment.

From spokesman Chris Nicholas:

It's no secret that Senator Specter was formerly a Republican just as it is no secret that since his critical deciding vote for the Economic Recovery Act he rejoined the Democratic Party. Since then he has been overwhelmingly endorsed for re-election by the Pa. Democratic Party, the Pa. AFL-CIO and the state’s two largest LGBT groups -- along with Senator Casey, President Obama, Vice President Biden and Gov. Rendell. The Democrats that Democratic voters know and trust trust Arlen Specter. So far, Cong. Sestak's highest profile endorsement has come from then-Congressman Eric Massa.

As President Obama said last year about Senator Specter, “You've got to make sure that you support somebody who's got the savvy and intelligence and the tenacity to actually get things done. That's who Arlen Specter is.  I'm proud to call him a friend.  I am glad that he is in the Senate.”