“It is difficult to cast a negative vote on someone with the qualifications and background of Dean Kagan, but we have a major problem of institutional standing to find out from a nominee what the nominee thinks on important questions,” Specter said, referring to her title as dean of Harvard Law School.

“I have gone to some length to try to find out more about Dean Kagan. In the absence of being able to do so and to have a judgment on her qualifications, I am constrained to vote no,” he said.

Seven Republicans voted for Kagan, including Sens. Jon Kyl (Ariz.), Tom CoburnThomas (Tom) Allen CoburnPaul Ryan should realize that federal earmarks are the currency of cronyism Republicans in Congress shouldn't try to bring back earmarks Republicans should know reviving earmarks is a political nightmare MORE (Okla.) and Orrin HatchOrrin Grant HatchOvernight Tech: Uber exec says 'no justification' for covering up hack | Apple considers battery rebates | Regulators talk bitcoin | SpaceX launches world's most powerful rocket Overnight Cybersecurity: Tillerson proposes new cyber bureau at State | Senate bill would clarify cross-border data rules | Uber exec says 'no justification' for covering up breach Hatch introduces bipartisan bill to clarify cross-border data policies MORE (Utah).
Specter was also a Republican member of the Senate Judiciary Committee, which declined to take up Kagan's nomination to the U.S. Court of Appeals for the D.C. Circuit in the late nineties. Former President Bill ClintonWilliam (Bill) Jefferson ClintonLongtime Clinton confidant blames Comey for 2016 loss Trump’s national monument rollbacks take effect A year after Obama, Dems still looking for replacement MORE nominated her to the bench in 1999.  

Recent polls show Sestak has pulled ahead of Specter in the primary race.
 
A new Muhlenberg College poll gives Sestak a four-point lead, 46 percent to 42 percent. A new Rasmussen poll shows Sestak ahead of Specter, 47 percent to 42 percent.
 
Sestak has gained political traction by raising Specter’s ties to prominent Republicans such as former President George W. Bush and former Alaska Gov. Sarah Palin.
 
Sestak launched an ad earlier this month with footage of Bush praising Specter as “a firm ally” he could “count on.”