WASHINGTON -- President Barack Obama today will formally announce the most aggressive and expansive national gun-control agenda in generations, as he presses Congress to mandate background checks for all firearm buyers and prohibit assault weapons and high-capacity ammunition clips.
The announcement will set off a fierce confrontation with Congress over an issue that has riven American society for decades. Mr. Obama's far-reaching firearms agenda has, at best, tepid support from his party leaders and puts him at loggerheads with Democratic centrists.
Days before his second inauguration, Mr. Obama is seeking to drive the guns debate in a way that contrasts with the accommodating approach he often took during his first term. In the weeks ahead, he will attempt to rally popular support to bend the will of lawmakers to vote for what he considers the ideal, not merely the possible.
"Yes, we can reduce gun violence, but it's something we have to do together," White House press secretary Jay Carney told reporters Tuesday. "It's something that cannot be done by a president alone. It can't be done by a single community alone, or a mayor or a governor or by Congress alone. We all have to work together."
Mr. Obama will begin this effort today in the presence of children who wrote him letters after last month's mass shooting at an elementary school in Newtown, Conn., and who have been invited to Washington to attend the rollout.
In addition to background checks and restrictions on military-style guns and ammunition magazines, Mr. Obama is expected to propose mental health and school safety initiatives such as more federal funding for police officers in schools, according to lawmakers and interest-group leaders whom White House officials briefed on the plans.
Mr. Obama also is expected to present as many as 19 executive actions that his administration will take, the lawmakers and advocates said. These steps include enhanced federal scientific research on gun violence and a modernized federal database system to track guns, criminals and the mentally ill. Most of these actions are relatively narrow in scope, however, and experts have said that without accompanying legislation, they will do little to curb gun violence, at least in the near term.
Asked about the constraints on Mr. Obama's executive powers, Mr. Carney said, "It is a simple fact that there are limits on what can be done within existing law."
After Vice President Joe Biden led a month-long task force, Mr. Obama decided to push an expansive agenda that in many ways represents his liberal base's wish list, rather than proposals that may be more politically viable to a divided Congress. Mr. Obama's proposals amount to the most comprehensive federal regulations of the firearms industry since 1968, when President Lyndon B. Johnson acted in the aftermath of high-profile assassinations.
"My starting point is not to worry about the politics," Mr. Obama said. "My starting point is to focus on what makes sense, what works, what should we be doing to make sure that our children are safe, and that we're reducing the incidents of gun violence." Lawmakers, he added, "are going to have to have a debate and examine their own conscience."
Already, there are warning signs about the hurdles Mr. Obama's agenda may face on Capitol Hill. Senate Majority Leader Harry Reid, D-Nev., said it would be exceedingly difficult to pass an assault-weapons ban, which appears to be the most polarizing of Mr. Obama's proposals.
"Let's be realistic," Mr. Reid told a Nevada PBS affiliate last week. "In the Senate, we're going to do what we think can get through the House, and I'm not going to go through a bunch of these gyrations just to say we've done something."
House Minority Whip Steny Hoyer, D-Md., echoed that calculation Tuesday by acknowledging the difficulties that gun-control legislation would face in the Republican-led House. "That's been the case based on past history," he told reporters.
More than half of all Americans say the Newtown shootings have made them more supportive of gun control, according to a Washington Post-ABC News poll released Monday. An assault-weapons ban has the support of 58 percent of Americans, the poll shows.
In New York, Democratic Gov. Andrew Cuomo on Tuesday signed into law what he called the most comprehensive package of state gun-control measures in the nation that includes. an expanded ban on assault weapons.
Congress will take up the federal proposals next week -- first in the Democratic-controlled Senate before advancing to the House. Gun control will be only one point of friction between the White House and the Capitol. Policy fights loom over raising the nation's debt ceiling as well as overhauling immigration laws.
Mr. Obama's gun-control proposals are sure to face stiff opposition from the National Rifle Association, which released a video Tuesday on its website calling Mr. Obama an "elitist hypocrite" for having the Secret Service protect his daughters at school while voicing skepticism about an NRA effort to place armed guards in all schools.
Lawmakers who have been part of Mr. Biden's discussions said the White House is well aware of the political difficulty they face.
• New York approves gun law; protesters demand Wal-Mart drop assault weapons. Page A-8