NRA officials are unyielding in their opposition, with spokesman Andrew Arulanandam saying, “We have a politically savvy and a loyal voting bloc, and the politicians know that.”
Obama and his backers find themselves in an unusual position — struggling to line up votes for a proposal that polls show the public overwhelmingly supports.
An Associated Press-GfK poll in January found 84 percent support for expanding background checks to include gun show sales. Near-universal checks have received similar or stronger support in other national surveys.
Polls in some Southern states have been comparable. March surveys by the Quinnipiac University Polling Institute found more than 9 in 10 people in Florida and Virginia backing expanded background checks, the same margin found in February by an Elon University Poll in North Carolina.
Analysts say politicians are loath to alienate the people who oppose broader background checks and other gun restrictions because they tend to be dedicated, single-issue voters.
The polling also points to a broader context that politicians are watching: The same Quinnipiac polls that show one-sided support for gun restrictions show people closely divided over whether Obama or the NRA better represents their views on guns.
“They can be for a specific kind of gun control, but they may be suspicious of efforts of other kinds that they think might come down the pike,” said Peter Brown, the Quinnipiac poll’s assistant director.
Sens. Chuck Schumer, D-N.Y., Joe Manchin, D-W.Va., and Mark Kirk, R-Ill., have spent weeks negotiating with GOP senators, hoping to find a formula that could win the needed bipartisan support.
“I’ll wait and see the outcome of that,” Sen. Mark Begich, D-Alaska, said of those talks, adding that the message his constituents give him is, “Don’t take away our rights, our individual rights, our guns.”
Other moderate Democratic senators who could be tough for supporters of broader background checks to persuade include Heitkamp of North Dakota, Mary Landrieu of Louisiana, Kay Hagan of North Carolina, Max Baucus of Montana and Mark Pryor of Arkansas.
Also targeted by Bloomberg’s ads are 10 Republican senators, including Jeff Flake of Arizona, home of ex-Rep. Gabrielle Giffords, who was severely wounded in a mass shooting, the retiring Saxby Chambliss of Georgia and moderate Susan Collins of Maine.
The Senate gun bill also would increase penalties for illegal gun sales and slightly boost aid for school safety.
White House spokesman Josh Earnest said Obama will travel to Denver Wednesday to talk to local leaders about Colorado’s efforts to reduce gun violence.