Arlen Specter is not guaranteed the Democratic nomination, no matter what kind of deal he has cut with Democratic power players in Pennsylvania. He already has a primary opponent in Joe Torsella (D), and Rep. Joe Sestak (D) hasn’t ruled out a shot at the Senate, either.

There are many reasons why Republicans have thought fondly of Specter over the years, and all of these reasons provide fertile ground for attacks from the Left. The Employee Free Choice Act, as Jim Geraghty points out, will be item number one. Specter isn’t just on the wrong side, he’s actually flipped to the wrong side. But sources in Pennsylvania fully expect Specter’s earmarks for abstinence funding, his vote for the 2001 Bush tax cuts, and his help in ushering Sam Alito and John Roberts through the Senate Judiciary Committee to take center stage in any Democratic primary.

Nor is Pat Toomey guaranteed the Republican nomination, although he will probably begin with a large fundraising lead. Former Pennsylvania Gov. Tom Ridge (R), Senate President Pro Tem Joe Scarnati (R), and Rep. Jim Gerlach (R) are all possible aspirants. Toomey’s folks are concerned about this — especially about Ridge — to the point that they want to make a show of strength right away and show the breadth of their support. They alerted me to the fact that House Minority Leader John Boehner (R, Ohio) had made some warm comments about him to the Washington Times editorial board, which Boehner’s political staff shared with me:

“I’m a Toomey supporter, he’s been my friend for a long time since he first ran for Congress, strong Republican, strong conservative, and someone who’d make a great U.S. Senator.”