Vice-president Joe Biden warned on Thursday that "there is a moral price to be paid" for inaction over gun control laws and criticised politicians "more concerned about your political survival" than the safety of America's children.
Speaking at a gun violence forum in Danbury, Connecticut, 10 miles from the Newtown school where 20 children died in a shooting attack in December, Biden praised the courage shown by families of the Newtown victims in dealing with the tragedy. But, in a passionate address, he drew contrast with the response of some politicians in the wake of the attack, and called on Congress to "show some courage too".
"I say to my colleagues who will watch this and listen to this: if you're concerned about your political survival, you should be concerned about the survival of our children. And guess what? I believe the price to be paid politically will be to those who refuse to act."
Biden said America has "changed position" over gun control after Newtown. He said: "We should all know the American people are with us. We should know there is a moral price to be paid for inaction."
But in a sign of the battle ahead over the implementation of the White House's proposed gun control laws, which include universal background checks and a ban on semi-automatic rifles, the National Rifle Association ran a series of advertisements in key states on Thursday morning, criticising the plans for gun reform.
The NRA opposes any changes to gun laws, and published adverts in newspapers in Arkansas, Louisiana, Maine, North Carolina and West Virginia that claimed Obama's gun proposals would be ineffective. The states were carefully chosen – each is a traditionally Republican stronghold with Senate re-elections coming next year.
Democratic senators in Arkansas, Louisiana, North Carolina are vulnerable in the 2014 mid-terms, while moderate Republican Susan Collins faces a re-election campaign in Maine. In West Virginia, Joe Manchin will retire.
Biden appeared to aim his speech at those who might be wavering in their commitment to stricter legislation – or who are yet to commit their support.
"I can imagine how we will be judged as a society," he said. "I can predict what will be written of us, 20 or 30 years from now, if we do not act."
He attacked "the organised opposition" who criticise the government's plans as an infringement of their second amendment rights.
"Let me say it now, in front of the press. No law abiding citizen in the United States of America has any fear that their constitutional rights would be infringed in any way. None. Zero."
Biden added: "I've also been told they say: 'There are too many of these weapons out there already, so why worry about putting more out? The ban will have no effect.' That's certainly no argument to continue to proliferate weapons that we don't think are healthy in society."
Biden formed a taskforce after the Newtown shootings, to explore ways to reduce gun violence. He presented his proposals to Obama in January, recommending universal background checks for all gun sales – closing the so-called "gun-show loophole" – and a ban semi-automatic weapons and high capacity magazines.
The conference had featured a discussion of legislation and better mental health provisions, which the White House's proposals also address. Held at Western Connecticut University, about 10 miles from Newtown, the forum was hosted by Connecticut senators Richard Blumenthal and Chris Murphy, and congresswoman Elizabeth Etsy.
Connecticut's governor, Dannel Malloy, used the event to unveil his own gun law proposals, warning that "we run the risk of letting a critical moment in our state's history pass".
Connecticut already has some of the strictest legislation in the country, but Malloy, who has expressed dissatisfaction with the pace of the Connecticut legislature's response, said there was a need to expand the permitting process to track more guns.
Some of Malloy's suggestions echoed the White Houses proposals, but Malloy also specifically suggested limiting magazines to "10 rounds or less", and said the definition of "assault weapon" should be expanded to include any include semi-automatic weapons that has at least one "military-style feature". Such a proposal would outlaw the Bushmaster weapon used in the Newtown shooting.
Malloy said he had written to legislators outlining his "clear commonsense steps", which include a combination of law changes, executive orders he can impose, and recommendations to the commission he established in the aftermath of the Newtown tragedy.
Speaking to reporters afterwards, Malloy said Biden's visit had "galvanised" support. "As he said, American people are with us," he said. "The vice-president demonstrates what you've seen at the highest levels in the federal government. An absolute riveting, unstinting commitment to reducing gun violence in this country."
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