Prominent gun rights advocates in the US government are now calling for a national discussion about curbing gun violence - signalling that the Connecticut primary school massacre could be a tipping point in a debate dormant for years.
White House officials said President Barack Obama would make preventing gun violence a second-term policy priority, but it was unclear what he would pursue or how and aides said stricter gun laws would be only part of any effort.
The President met his vice president Joe Biden and a handful of Cabinet members on Monday, including attorney general Eric Holder, education secretary Arne Duncan and health and human services secretary Kathleen Sebelius, to begin discussions on ways the country should respond to the Newtown shootings.
Mr Obama has called for a national dialogue after other mass shootings during his presidency, only to see those efforts take a back seat to other pressing issues.
This time the President has vowed to use "whatever power this office holds" to safeguard American children against gun violence, suggesting he may put political muscle behind an assault weapons ban. He has long supported reinstating the ban, which expired in 2004, but never pressed for in his first term. Liberal Democrats on Capitol Hill are already laying the groundwork for legislation to outlaw the military-style arms.
And Virginia's Mark Warner, one of the few Senate Democrats who has found favour with gun rights groups, reversed course to back restrictions on assault weapons. "The status quo is not acceptable any more," he said.
Democratic Senate majority leader Harry Reid vowed Congress would soon "engage in a meaningful conversation and thoughtful debate about how to change laws and culture that allow violence to grow". The Senate Judiciary Committee will hold hearings on gun violence early next year.