Specter expects a primary challenge, but whom will it be?

U.S. Sen. Arlen Specter: Getty Images PhotoST. PAUL, MINN. -- U.S. Sen. Arlen Specter (R-Philadelphia) said Tuesday that he expects an opponent in the primary when he runs for re-election in 2010.

"I do," he told reporters while seated in a cafe in the downtown Crowne Plaza Hotel. "I think I'll have an opponent in the primary, and I think I'll have an opponent in the general."

The longtime senator did not seem concerned about a potential challenge. He quoted a line from pitching great Satchel Paige that he said describes his election philosophy.

"Never look back -- somebody may be gaining," he said.

Speculation over Specter's future, while not the focus of speculation for the Pennsylvania delegation during a presidential election year, has been a topic of conversation this week. Specter, who angers some conservatives who say he is too moderate, fended off a stiff challenge from Pat Toomey in 2004, defeating the former congressman by fewer than 20,000 votes of the more than 1 million cast.

U.S. Rep. Jim Gerlach (R-Upper Uwchlan Township) has been rumored most prominently as a potential Republican challenger, although some insiders doubt the southeast Pennsylvania congressman will take the plunge. Pat Toomey is typically the only other name mentioned as a potential candidate, and most predict he'll run for governor in 2010 instead.