Former Rep. Pat Toomey (R-Pa.) will challenge Sen. Arlen Specter in a primary for the second straight cycle, according to Pennsylvania GOP sources. The Allentown Morning Call reported Thursday that two friends of Toomey’s have said the Club for Growth chief has decided to enter the race. Toomey narrowly lost to Specter in a 2004 primary by less than 1 percent and recently said he was considering another run. The paper quotes Richard Thulin, leader of the Lehigh Valley Republican Network, saying in an e-mail to supporters that "Pat's formal announcement will be forthcoming. "Interesting news," he wrote. "Pat Toomey...