Sen. Jim Risch is the leading advocate for 14 Republican senators seeking to block a vote on legislation expanding background checks for gun purchases in the wake of December's school shooting in Connecticut.
CNN's Anderson Cooper said Risch was the only one of the 14 who would agree to appear on his show Tuesday night. Risch and Idaho Sen. Mike Crapo joined 12 colleagues in a letter to Majority Leader Harry Reid, D-Nev., Monday saying they would support a filibuster to stop a vote.
Risch conceded that Reid, with the help of Republicans including Arizona Sen. John McCain, will likely muster the 60 votes necessary to stop a filibuster, limit debate and force a vote. The procedural vote is scheduled Thursday.
"I think there's clearly 60 votes to override a filibuster," Risch told Cooper. "There's going to be a debate this week."
Added Risch: "I'm committed to defeat any legislation that interferes with a law-abiding citizen's right under the Constitution - which is a right just like freedom of speech, freedom of religion and freedom of association in Amendment One. Amendment Two gives every American the right to keep and bear arms."
Risch appeared on "CBS This Morning" on Wednesday, defending the Senate minority's most powerful procedural tool. "The filibuster is simply a tactic to stop the bill from passing," he said. "If you're successful on the filibuster, it's over, it's done, and that would be my preference."
Background checks some Republicans support are ineffective, Risch said. "One of the problems we have ... is focusing on expanding a background check system that simply does not work and casts a burden on people that are exercising a constitutional right."
In an interview Tuesday on National Public Radio, Risch defended the filibuster while expressing sympathy for the families of 20 children and six adults killed in Newtown, Conn. "As far as firearms deaths are concerned, they're awful. They're terrible. I'm a father and a grandfather. I can't imagine if you had someone who was caught in it."
Crapo was unable to accommodate requests from CNN, MSNBC and the New York Times, said spokesman Lindsay Nothern. But Crapo told KVNI radio in Coeur d'Alene he opposed "any role for the federal government in restricting the right to bear arms," including background checks.
Dan Popkey: 377-6438, Twitter: @IDS_politics