Democrats are using the fact that four retiring Republican senators voted for Supreme Court nominee Sonia Sotomayor to argue the nominee was well-qualified and that the GOP base is outside of the American mainstream.

    The Senate's 68-31 vote on Thursday made Sotomayor the first Hispanic on the court and only the third woman, coming 72 days after President Barack Obama nominated the New York native.

    Her supporters included nine of the 40 Senate Republicans: Mel Martinez (Fla.), George Voinovich (Ohio), Judd Gregg (N.H.), Kit Bond (Mo.), Lindsey Graham (S.C.), Susan Collins (Maine), Olympia Snowe (Maine), Richard Lugar (Ind.) and Lamar Alexander (Tenn.). Of those, Martinez, Voinovich, Gregg and Bond are retiring.

    "I think it was an exceptional nominee that garnered their support, but I also think that if you're free from seeking re-election, you're even freer from your party's pressure or the NRA's pressure," said Democratic Senatorial Campaign Committee Chairman Robert Menendez (N.J.).

    The National Rifle Association had opposed Sotomayor, and had announced it was "scoring" the vote in its future evaluations of lawmakers.

    Menendez also said the retirees' votes for Sotomayor could come into play in next year's Senate races - such as Florida, where centrist GOP Gov. Charlie Crist faces a primary from Marco Rubio, a former state House speaker who is considered far more conservative. Martinez delivered an eloquent Senate speech supporting Sotomayor, Menendez noted, but Crist had announced his opposition.

    "Charlie Crist is going to have to explain why Mel Martinez can make all the comments he made and he's appealing to the hard right," Menendez said. "That may be great in a primary election, but it's going to be troublesome in the general election with a huge Latino population. Those are the type of examples we're talking about."

    Gregg, Bond and Voinovich all denied their re-election decisions were a factor in their votes on Thursday, noting that they have supported Democratic nominees in the past. Bond pointed to his vote for Ruth Bader Ginsburg in 1993, while Gregg noted he supported both Ginsburg and Justice Stephen Breyer in 1994.

    "Our job is not to judge the political philosophy of the nominees," Bond told The Hill. "I vote the same way whether I'm running for re-election or not."

    Likewise, Voinovich downplayed any suggestion of freedom from the GOP base.

    "My conscience - I'm never free of that," he said. "I try to call them as I see them, and I think the woman was qualified."

    Martinez announced Friday he intends to resign at the end of August, after previously announcing he wouldn't seek re-election.

    "I really do think it's about feeling liberated," Jennifer Duffy, a senior analyst at The Cook Political Report, said of the retirees' votes. "The pressure from the base matters a whole lot less. Voinovich and Bond have seemingly been doing this for a while, but even more so lately. They're clearly going to do what they want as long as they're there."

    Voinovich, a well-known moderate, ruffled feathers last month when he told an Ohio newspaper the Republican Party "has been taken over by southerners," which brought a backlash from conservative Sen. David Vitter (R-La.). Bond, for his part, delivered a well-received floor speech announcing his support for Sotomayor and warning that both political parties should not oppose Supreme Court nominees based on their philosophy.

    "He was basically saying, 'At some point it's got to stop,' " said Duffy.

    At least one Republican leader agreed that retirements likely played a role in the GOP vote for Sotomayor, although the party didn't whip the vote beforehand.

    "Everyone came to different conclusions, but I do think if you're not running for re-election, you'll vote more freely," said GOP Policy Chairman John Thune (S.D.).