Six years after coming within a few percentage points of ousting Sen. Arlen Specter (R-Pa.), former Rep. Pat Toomey (R) is telling people he will mount another primary bid against the veteran Keystone State Senator in 2010, an Allentown Morning Call blog reported late Thursday afternoon.

Toomey just this week had reversed course and said that he was contemplating another run for Senate, after telegraphing that he was more interested in a run for governor in 2010. Toomey has been the president of the conservative, anti-tax group the Club for Growth since leaving Congress at the end of 2004.

According to the Morning Call blog item, Toomey has begun telling friends that he will run for Senate again in 2010.

Specter is considered one of the more vulnerable Senators up for re-election next year, in part because of his vulnerability in a primary and because of Pennsylvania’s increasingly Democratic slant. Specter was one of three Senate Republicans to vote in favor of the economic stimulus legislation that passed Congress last month, a move that Toomey has said was key in his decision to rethink a Senate bid.