(CNN) - It's official. Former Rep. Pat Toomey is challenging Pennsylvania Sen. Arlen Specter for his Senate seat, again.
Toomey formally announced his 2010 Senate bid Wednesday, the second time he will challenge the incumbent Pennsylvania senator after running an unsuccessful primary campaign against him in 2004.
"I'm running against Arlen Specter in the Republican primary because we need a new direction and positive solutions," Toomey says on his campaign website, ToomeyForSenate.com.
Toomey announced Monday he would begin taking steps to challenge Specter, but formally announced his candidacy Wednesday. Specter had already begun releasing campaign ads targeting his opponent before the former congressman made his announcement official.
Toomey's replacement at the head of the limited-government, anti-tax Club for Growth is former Rep. Chris Chocola. The new president announced Wednesday the group was making its first two Senate endorsements of the 2010 cycle, backing incumbent Republicans Jim DeMint and Tom Coburn.