No surprise here: Barack Obama's nomination of Elena Kagan for the Supreme Court has become an issue in Pennsylvania's Senate campaign. 

Congressman Joe Sestak, who has been challenging incumbent Arlen Specter in an increasingly spirited Democratic primary, has used the pick to pick a fight. While praising Kagan as "a respected legal mind ... and a key domestic policy adviser for President Bill Clinton," Sestak is also using her nomination as a cudgel to beat up his rival. 

Sepcter, he noted, voted against Kagan's nomination as Solicitor General back in March 2009, shortly before Specter swapped parties. Specter said Kagan hadn't answered his questions adequately, though seven other Republicans voted for her. (Interestingly, Kagan specifically declined to answer questions about "specific Supreme Court cases and Constitutional doctines." Count on hearing plenty more of that in the months ahead.)

"I expect Senator Specter may backtrack from his earlier vote," Sestak says in a statement. "[B]ut the people of Pennsylvania have no way of knowing where he will stand after May 18."

Sestak then helpfully reminds us of Specter's interrogation of Anita Hill, and of Rick Santorum's allegations that Specter pledged to support George W. Bush's court nominees in exchange for political backing.

Yes, very well played, Congressman. Still, there's a bit of irony here. Kagan is, by all accounts, an absolutely centrist choice ... a choice made by an administration that didn't want to risk stoking Republicans with an ideological battle. Even before she was picked, there were some grumblings from lefties who want a strong ideological counterweight to the likes of Antonin Scalia. Which means that Sestak -- who is running as a liberal insurgent in defiance of the political establishment -- is touting the merits of an establishmentarian judicial pick. Obama's pick of Kagan is, arguably, of a piece with his decision to back Specter. And yet Sestak is rallying behind the former so he can beat up on the latter. 

Not sure you can blame Sestak for using whatever ammunition comes to hand. But Arlen Specter ain't the only guy who might be playing political games with a Supreme Court court nominee. 

ADDED:  And here's Specter on Kagan:

"I applaud the President for nominating someone who has a varied and diverse background outside the circuit court of appeals. I voted against [Kgan] for Solicitor General because she wouldn't answer basic questions about her standards for  handling that job. It is a distinctly different position than that of a Supreme Court Justice.

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." 

Actually, if I had to bet, she's gonna stymie Specter as a Supreme Court nominee the same way she stymied him as a nominee for solicitor. Probably more so. But it sounds like Specter's OK with that -- Kagan is seeking a different job, and Specter's own position is so much less secure. Weird, though, to think that Supreme Court justices -- whose rulings affect us far more directly, and who stick around a lot longer than a presidential appointee -- are held to a lower standard of disclosure.