(CNN) - Sen. Chris Murphy doesn't share the National Rifle Association's assessment that Congress won't pass an assault weapons ban.
"I think (the NRA) is wrong," the Connecticut Democrat said Sunday on CNN's "State of the Union." "I think that this issue is going to continue to move."
On the same CNN program, NRA President David Keene said earlier he doesn't think there's enough support to get an assault weapons ban, or restrictions on high-capacity magazines, through both chambers of Congress.
Murphy, however, shot back, saying when the "president puts the full weight of their office behind legislative change, that certainly means something." The freshman senator was speaking on the show from Newtown, Connecticut.
Following last month's shootings at the Newtown elementary school, President Barack Obama tapped Vice President Joe Biden to lead a task force that would come up with proposals no later than this month to reduce gun violence. While meeting with a wide variety of stakeholders in the gun debate last week, Biden cautioned that "the president is going to act" and mentioned that executive orders could be issued.
Murphy said he does see movement on Capitol Hill toward wanting serious change in federal gun laws. He pointed to pro-gun Democrats with high ratings from the NRA, such as Sen. Joe Manchin of West Virginia and Sen. Mark Warner of Virginia, both of whom have been outspoken on a need for change. He also mentioned conservative Rep. Phil Gingrey of Georgia, who recently said he favored some forms of gun control.
"That's a sea change if people like that in the Republican House Caucus are willing to look at this," Murphy told CNN chief political correspondent Candy Crowley. "Newtown fundamentally changed things, and the NRA just doesn't get this. They've got to come to the table on gun control, just as they're saying they're coming to the table on mental health, because their previous allies and backers in the House and the Senate aren't with them anymore."
He took aim in particular at the lobby's influence.
"The NRA does not represent gun owners anymore. This is not your father's NRA. It represents gun manufacturers," Murphy said. "They make tens of millions of dollars off of purchases of guns."
Since the shooting last month, the NRA has added 100,000 new members, bringing its total membership to 4.2 million, NRA officials told CNN. Because of the increased attention on the issue, the officials think the group will soon hit 5 million.
Murphy pointed to the organization's "roundup" program, which encourages customers to round the cost of their purchase up to the next higher dollar amount and give the difference to the NRA.
The NRA's Keene, however, argued with that notion earlier on "State of the Union," saying manufacturers are "not our constituency."
"Our constituency is twofold," he said. "It's the American people who want to own guns and use them legally, and it's the Second Amendment itself."
While the NRA sharply disagrees, Murphy maintained that an assault weapons ban would help stop more mass shootings, and he vowed to vote for such legislation if it comes to the Senate floor.
"There would still be little boys and girls alive in Newtown today, I believe, if you had banned assault weapons and these high-capacity magazine clips," he said. "And that's something we can do and do now."
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