The politically treacherous debate over the nation’s gun laws has thrown President Obama’s second-term negotiating style into sharp relief.

In earlier legislative skirmishes, Obama was pragmatic above all, making a first offer and then a second and a third as he sought compromise with a bitterly divided Congress.

But in his legislative push to curb the nation’s gun violence, Obama’s willingness to make concessions has been absent, at least so far. The president set a clear marker — to enact the toughest gun restrictions in generations — and has since worked to rally the public to his side while waiting for wavering lawmakers to come along.

Obama is all but ignoring the Republican-controlled House as he waits for a bipartisan majority to emerge in the Senate, hoping to use it as leverage to force a vote from House Speaker John A. Boehner (R-Ohio).

“It’s clear that the dynamic of the second term will be to go to the Senate, try to build a bipartisan majority there for action, and then take it to the House and put John Boehner in the position where he’s the only person in town saying no,” said Steve Elmendorf, a Democratic lobbyist and former House leadership aide.

After the president delivers the State of the Union address, there are rebuttals from either Democrats or Republicans, and sometimes other parties. Take a look back at some of the most memorable State of the Union responses of the last 10 years. (Nicki Demarco/Sandi Moynihan /The Washington Post)

Although Obama’s State of the Union address on Tuesday will focus heavily on the economy and fiscal matters, the president is also expected to pressure Congress anew to act quickly on gun control.

Democratic lawmakers are bringing shooting victims from their home states to sit in the gallery. The White House said victims of gun violence will sit with first lady Michelle Obama.

The president’s confident approach on guns is particularly striking given the deep divisions within the Democratic Party over the issue.

The divide is more pronounced in the Senate than in the House, where many Democrats have reliably liberal constituencies. A significant number of Senate Democrats, by contrast, represent states with deep hunting traditions or are worried about votes that might antagonize the National Rifle Association.

Yet the president called again last week for a vote on an assault weapons ban, the most polarizing of his proposals. Obama is pursuing a similar strategy for other issues dominating his second-term agenda, from comprehensive immigration reform to staving off the deep spending cuts known as the sequester.

Obama may still return to a more accommodating approach; he often says that he won’t let the perfect be the enemy of the good. But his recent strategy reminds some longtime congressional observers of former President Ronald Reagan, who also drew firm lines — while still allowing for compromise in the end.

“What Reagan was able to do so successfully was to lay out a firm, tough and pure position and hold to it while things shook down and the other side moved, and waiting for them to come much closer to where he wanted them to be,” said Norman J. Ornstein of the American Enterprise Institute. “I see Obama’s public statements on guns now being much more of that than anything else.”

The legislative process should begin by the end of February, when Senate Judiciary Committee Chairman Patrick J. Leahy (D-Vt.) plans to stitch together several proposals, including requiring background checks for all gun buyers, making gun trafficking a federal crime for the first time and limiting the size of ammunition magazines.

Expansion of background checks is the most popular proposal and enjoys overwhelming support in public polls. Four key lawmakers — Sens. Charles E. Schumer (D-N.Y.), Joe Manchin III (D-W.Va.), Tom Coburn (R-Okla.) and Mark Kirk (R-Ill.) — are drafting the legislative framework for a deal.

To accommodate gun rights proponents, the legislation could include limited exceptions for guns transferred between family members or rented for sporting purposes, according to senior aides.

For decades, liberal lawmakers — many of whom represent cities plagued by gun violence — have pushed for additional gun restrictions. They’ve wanted to reinstate an assault weapons ban ever since one version expired in 2004.

At a news conference last week, Rep. Elijah E. Cummings (D-Md.) of Baltimore spoke about the shooting death of a 20-year-old nephew and said he sympathized with victims’ families.

“It is a painful thing to see your blood splattered on the walls of an apartment, to see tissue from your loved one splattered on walls,” Cummings said. “I understand why they are desperate for action.”

Over the years, however, action has been stymied by more moderate Democrats. Party leaders have steered away from discussions of guns — a strategy designed to win over moderate swing voters. But top Democrats think the Newtown school shooting, in which 20 children and six adults died, altered the political landscape.

“I see this whole gun issue as an opportunity, not a toxic landmine,” former President Bill Clinton told House Democrats last week. “I guarantee you, a lot of people from where I grew up were asking themselves this practical question: If that young man had had to load three times as often as he did, would all those children have been killed?”

In the Senate, at least 10 Democrats must defend their seats in 2014 in states with sizable gun-owning populations. Many of them have not taken positions in the gun debate, perhaps because they are struggling to find middle ground. But they also have not championed the NRA’s status-quo position, an indication that they might vote for expanded background checks or other measures.

“There may be substantive differences over things like assault weapons, but there’s no hostility, and there’s a genuine desire to work not only with Obama but to find Republican allies to work with as well,” said Matt Bennett, a senior vice president of Third Way, a centrist think tank.

At the moment, the political imperatives of Obama and those of Senate Democrats up for reelection are in conflict, something the president acknowledged last week when he addressed House Democrats at their annual retreat.

“There are regional differences here, and we should respect those,” Obama said. “Guns mean something different for somebody who grew up on a farm in a rural community and someone who grew up in the inner city.”

Consider Manchin, a gun rights advocate who signaled after Newtown that he might support some gun-control measures. Schumer quickly reached out to him, and their coalition grew to include Kirk and Coburn. The senators and their aides have been tight-lipped in recent days about their talks — a sign in Washington of progress behind the scenes.

One sticking point is Coburn’s desire to revamp how the Justice Department manages the system for background checks. Coburn also wants an exemption from background checks for people selling or giving their firearms to relatives, according to senior aides.

Another source of potential tension is the proposed ban on more than 150 military-style assault weapons, authored by Sen. Dianne Feinstein (D-Calif.). Despite majority support for banning assault weapons in most polls, her bill faces long odds on Capitol Hill.

“I think we all know this is an uphill battle,” Feinstein said in a recent interview. “That doesn’t mean we shouldn’t try.”

Congressional aides expect Feinstein to decide whether to ask Leahy to include her proposal as part of his guns bill or to have a separate up-or-down vote. Obama said last week that the proposal “deserves a vote in Congress, because weapons of war have no place on our streets.”

Gun control is a more emotional issue in the House. Some House members are gunshot survivors or, like Cummings, have personal ties to gun violence. Others, like Rep. Mike Thompson (D-Calif.), who fought in the Vietnam War and shoots for sport, are protective of gun culture.

“I’m a hunter and I’m a gun owner and I believe that we should protect law-abiding citizens’ rights to own firearms,” Thompson said last week. “I’m not interested in giving up my guns, and I wouldn’t ask anyone else to give up their guns.”