Former Massachusetts Gov. Mitt Romney on Tuesday endorsed Sen. Arlen Specter's GOP opponent in the 2010 Pennsylvania Senate race, giving Pat Toomey the backing of one of the Republican Party's most influential members.
Romney, who ran unsuccessfully for his party's presidential nomination last year and is considered a top contender in 2012, announced his support for Toomey in Philadelphia.
Specter's seat is a prime target for Republicans, since the veteran and moderate lawmaker switched from the Republican to Democratic Party earlier in the year over fears that Toomey would trounce him in the primary.
Now Specter faces both Democratic and Republican challengers.
Calling him the "man for the job," Romney pledged in a fundraising e-mail to work "very hard" toward Toomey's election.
But Specter's not suffering from a dearth of high-profile support.
President Obama attended a Philadelphia fundraiser for Specter last month, calling on supporters to "fight" for Specter in the coming year.