President Barack Obama has raised the stakes for national action to reduce gun violence following the Newtown, Conn., elementary school massacre, but the White House and top Democrats in Congress continue to choose their words carefully on a subject that has bedeviled the party for two decades.

After Obama issued an urgent call to act Sunday night in Newtown — declaring, “We can’t tolerate this anymore” and vowing to use all the power of his office to find a solution to the issue — the White House on Monday declined to talk about any details.

“I don’t have a specific agenda to announce to you today,” White House Press Secretary Jay Carney said. He reiterated the president’s support for reinstating the assault weapons ban, pointing out that Obama has held that position since the measure expired in 2004. Carney said broadly that improving background checks was important.

But the president has done almost nothing to push for the assault weapons ban or other gun control measures in his first term. Other agenda items took precedence over a fight many in his own party didn’t want and didn’t think they could win against the powerful National Rifle Association’s lobby.

The odds remain stacked against any significant legislative action, and many other initiatives will compete for the nation’s attention.

The NRA hasn’t lost a major legislative battle in Congress in memory, and Democratic leaders, including longtime gun rights supporter Sen. Harry Reid, D-Nev., were in no mood to get bogged down in a gun debate after the other massacres that have occurred on Obama’s watch.

But over the weekend there was a palpable sense in the Capitol and at the White House that the faces of 20 little children slaughtered at an elementary school might prompt more than the usual moments of silence followed by partisan squabbling and, ultimately, inaction.

“There is an earthquake of a change that has come about,” Rep. Sheila Jackson Lee, D-Texas, said. “I feel a sense of urgency, but I also feel relief that something is finally going to happen. … I haven’t had this feeling before.”

Ironically, a conservative Democrat from West Virginia, Sen. Joe Manchin III, moved out front Monday with more specifics than the president. Manchin, a lifelong NRA member, called for gun control measures targeting large capacity gun clips as well as military-style assault rifles.

“I don’t know anyone in the sporting or hunting arena that goes out with an assault rifle. I don’t know anyone that needs 30 rounds in a clip to go hunting,” Manchin said Monday on MSNBC.

Manchin famously used a rifle to shoot a copy of the president’s cap-and-trade bill in one of his campaign ads. He’s an avid sportsman and represents exactly the kind of Democrat that gun control advocates need to win over to have a prayer of passing any legislation through Congress.

Moderate Sen. Mark Warner, D-Va., also spoke out on the issue, calling the Newtown massacre a “game changer.” And Rep. John Yarmuth, D-Ky., criticized himself for not speaking out against gun violence in the past.

Rep. Mike Quigley said he’s been in the House for four years without seeing a single hearing on gun issues. But the Illinois Democrat said he doesn’t fault the president for not pushing the issue.

“I don’t blame him. I know exactly what happened to Clinton after this in the mid-term elections. The reality is we need him to be a president for a second term, and the opposition to this maybe has finally turned,” he said.

Predictably, Reid’s tack was as restrained as the president’s. He echoed the idea that “every idea must be on the table,” but stopped shy of specifics Monday.

“We need to accept the reality that we are not doing enough to protect our citizens,” he said.

The majority leader and other senators, including Judiciary Chairman Patrick J. Leahy, D-Vt., promised a deeper look into gun violence, including hearings.

“I believe part of that healing process will require Congress to examine what can be done to prevent more tragedies like the ones in Newtown, Conn.; Aurora, Colo.; Oak Creek, Wis.; and Portland, Ore.,” Reid said.

Senate Majority Whip Richard J. Durbin, D-Ill., laid out the most detailed agenda in an op-ed in the Chicago Tribune — calling for an assault weapons ban, a ban on clips holding more than 10 bullets and limits on gun purchases. All are ideas that have been repeatedly offered and summarily ignored by Congress in recent years.

Congressional Republicans, meanwhile, generally kept their distance from the idea of legislative action. Minority Leader Mitch McConnell, R-Ky., kept his remarks squarely focused on condolences for the victims.

In recent decades, the NRA has not only won races but also dominated the messaging war.

On the campaign trail, Democrats and Republicans alike frequently referred to themselves as defenders of the Second Amendment. Republicans squabbled over who was more “pro-gun” in their primaries. Blue Dog Democratic Rep. John Barrow brandished his family’s “little Smith & Wesson” in a 30-second spot for his conservative Georgia district. He won.

Pro-gun-control positions mostly crop up in inner city House districts — and even there, candidates don’t bring it up often.

Former Rep. Jesse L. Jackson Jr. served as an exception last March, when he used the issue in a television advertisement criticizing his opponent, former Rep. Debbie Halvorson, a former NRA endorsement recipient, in the Democratic primary in the 2nd District on Chicago’s south side. It’s a region that’s been ravaged by gun violence.

And on Capitol Hill, Democrats have been so divided on guns that proposals for gun amendments on unrelated legislation are sometimes enough to sink them outright. Manchin, however, expressed hope that common ground could be found between the NRA and gun control advocates.

But it’s not clear how many other moderate Democrats will join the West Virginia senator, who won’t face the voters again until 2018, in a push for new laws. In 2014, Democrats play defense in 20 seats — many of them in red states such as Alaska, Alabama, Louisiana and Montana.

One of those incumbents, Senate Finance Chairman Max Baucus of Montana, is the only Senate Democrat to receive an “A+” rating from the NRA.

Niels Lesniewski contributed to this report.