On Wednesday, Judiciary Committee Chairman Patrick Leahy derided the National Rifle Association for announcing that it would be scoring senators' votes on the Sonia Sotomayor confirmation. "I would hope all senators would make up their mind based on what they saw or what they heard and not what any pressure group on the either right or left comes up with," the Vermont Democrat said at a press conference, which was co-hosted by Senate Majority Leader Harry Reid, D-Nev., in coordination with progressive interest groups.

But whether or not the NRA is pulling the strings, the Second Amendment is clearly one of the biggest concerns for Republicans voting against Sotomayor. Nineteen of the 26 Republicans who have already pledged to vote "nay" have mentioned the Second Amendment, gun rights or, more specifically, Sotomayor's ruling in Maloney v. Cuomo in official remarks or statements explaining their decision. Not surprisingly, senators from more conservative states were among those who placed the issue front and center in their remarks, including John Thune of South Dakota, Mike Johanns of Nebraska, and Roger Wicker of Mississippi.

The GOP Judiciary members who are voting against the confirmation didn't focus on the Second Amendment as much as other senators in their statements. John Cornyn of Texas, Charles Grassley of Iowa and ranking member Jeff Sessions of Alabama mentioned the Second Amendment only fleetingly, and Orrin Hatch of Utah didn't mention it at all. This suggests to some observers that those senators who are more knowledgeable on the issue rightly see the Second Amendment as less of a concern. "It seems that many Republicans are stretching for reasons to vote against her," said Marge Baker, executive vice president of the left-leaning People for the American Way. "And that's despite the fact that a number of Republicans on the Judiciary Committee concluded that her jurisprudence is totally within the mainstream."

As for the NRA's influence on the other side of the aisle, the votes of a handful of Democrats, especially those hailing from red states, could be telling. Ben Nelson of Nebraska, and Mark Begich of Alaska have both indicated they are still undecided. Blanche Lincoln of Arkansas, up for re-election in 2010, is one senator conservative activists have said could be vulnerable to NRA attacks.

So how much of a threat will the NRA's score be to senators up for re-election either in 2010 or later? "That's not a question for us to answer," said NRA spokesman Andrew Arulanandam. "That's a question for them to answer." He added that it's "relatively early innings in this session of Congress" to start debating how much influence this vote will have compared to other issues that may come up.

Brian Darling, director of Senate Relations at the conservative Heritage Foundation, said Sotomayor's confirmation is "not going to be an easy vote" for Democrats hailing from Western states. "If you get one Western state Democrat to vote no on Sotomayor, that could spell trouble for the nominee," he said. Darling also predicted that recent gun rights legislation widely supported by Democrats could "trickle down" and affect senators' confirmation votes. He pointed specifically to a recently rejected amendment proposed by Thune, which would have made it legal to carry concealed weapons across state lines. Twenty Democrats voted in favor, including Nelson, Lincoln and Begich.