President Barack Obama is seeking to defy both history and congressional reality in calculating that shifting public opinion will ease passage of the most expansive gun-control agenda in a generation.
A month after the shooting rampage that killed 20 students and six educators at a Connecticut elementary school, Obama Wednesday challenged Congress to pass legislation to reinstate a ban on sales of assault weapons, limit high-capacity ammunition clips, and mandate background checks for all gun buyers.
The $500 million proposal marks the first significant effort to curb gun violence in two decades. The plan, announced days before Obama's inauguration, guarantees a politically treacherous battle with Congress early in his second term.
"I have no illusions about what we're up against," Vice President Joe Biden said at the White House Wednesday. Obama had asked Biden to come up with recommendations following the shooting at Sandy Hook Elementary in Newtown, Conn.
Obama and his allies face intense opposition in Congress to stiffer gun regulations. The National Rifle Association, the largest lobby for gun owners and makers, has vowed to fight new limits.
"They have to fear the establishment of a national registry," he said, because such records of firearms owners would mean "the government could force them to sell those firearms back to the government" and that's "basically confiscation."
Along with reinstating the assault-weapons ban that expired in 2004 and limiting ammunition magazines to 10 rounds, Obama wants Congress to pass legislation that would prohibit the possession of armor-piercing ammunition and increase criminal penalties for gun trafficking.
Congress is preoccupied with a trio of fiscal deadlines in February and March, including the need to raise the nation's borrowing limit, and opposition to tightening gun regulations runs deep in the Republican-led House. In the Senate, Democrats lack the 60 votes needed to advance most major legislation.
In an effort to circumvent congressional opposition, Obama Wednesday signed 23 executive actions, including several designed to maximize prosecution of gun crimes and improve access to government data for background checks.
Going beyond those actions, administration officials acknowledge, will be challenging. "To make a real and lasting difference, Congress must act," Obama said Wednesday. "And Congress must act soon."
Decades of congressional inaction on gun-control measures suggests Obama's agenda could easily be undercut.
It was an obscure provision over "midnight basketball" for at-risk youths that almost derailed the 1994 assault weapons ban, and in 1999, attempts to tighten gun laws following mass killings at Columbine High School in Colorado failed after stalling for weeks in the U.S. House.
"It's not likely that Congress in the end will act, but I think it's possible that they will act," said Robert Spitzer, an author of four books on gun control, including "The Politics of Gun Control." "The door is open, not only because of the degree of outrage over this shooting. It just shocked people in the way that past shootings haven't," Spitzer said.
House Speaker John Boehner was noncommittal about the president's proposal, indicating no urgency in moving forward with gun legislation.
As a response to the Connecticut shootings, House Energy and Commerce Chairman Fred Upton, a Michigan Republican, plans hearings on mental health issues, and Republican lawmakers including Representative Frank Wolf of Virginia are pressing for warning labels on violent video games.
Other Republicans say new legislation isn't the solution to stemming gun violence.
"You can pass whatever law you want, and law-abiding people will abide by it. It's not going to deter anyone who wants to commit a crime," said Representative Trey Gowdy of South Carolina.
In the Senate, Dianne Feinstein, a California Democrat, plans to introduce another assault weapons ban, and Judiciary Committee Chairman Patrick Leahy, a Vermont Democrat, said Wednesday that he has scheduled a hearing on new proposals for Jan. 30.
A majority of Americans favor new gun-control measures, with support for banning high-capacity assault magazines at 65 percent and a prohibition on the sale of military-style weapons at 58 percent, according to an ABC News/Washington Post poll released Jan. 14.
The shooter in Newtown, Adam Lanza, used a Bushmaster semi- automatic AR-15 rifle and had ammunition magazines that held 30 rounds. Democrats say the shooting has caused a shift in the political ground on the issue and created an opening for action.
There is some bipartisan support in Congress for two of Obama's recommendations: a background check for all gun purchases and limits on high-capacity magazines like those used in many of the mass shootings at schools and universities over the past decade, according to Democrats, including Representative Carolyn McCarthy of New York.
Democrats face a tactical decision on how hard to push the assault weapons ban. That provision will probably face the toughest opposition in the House and could endanger passage of other initiatives.
"We're not going to get an outright ban" on assault weapons, said McCarthy, whose husband was murdered in a 1993 mass shooting on the Long Island Rail Road -- violence that prodded her into a political career.
"So are we going to waste time on heavy lifting, or are we going to try to work on something we can actually get passed?" she said. McCarthy is a member of a House panel of Democrats examining options for gun violence.
Democrats say that the background-check proposal has the best chance of passage among Obama's major proposals.
"Eventually a bill to strengthen background checks will pass," said Rep. Mike Thompson, a California Democrat who is heading the party panel on gun violence. "It's a great first step."
To overcome opposition in Congress to the gun-control measures, administration officials are seeking to rally popular support and enlist the help of law enforcement officials, religious leaders and victims of gun violence.
Over the past several weeks, administration officials have held 22 meetings with 220 organizations to develop their plans.
In 1993, President Bill Clinton signed the Brady Handgun Violence Prevention Act, which instituted federal background checks for firearms purchasers; a year later, he signed the assault weapons ban. Democrats controlled both chambers of Congress when the legislation was passed.
Clinton's efforts on limiting juveniles' access to guns and requiring background checks for firearm sales failed in 1999.
"Why did those two succeed and the others not?" said Chicago Mayor Rahm Emanuel, a Democrat who served in the U.S. House and was an adviser to both Clinton and Obama. "The later legislation wasn't as laser-focused on criminal access and prosecution."
Emanuel, who was speaking at a forum in Washington this week, advised those in Congress supporting Obama's proposals to focus on pushing legislation that has some bipartisan support, such as the background checks.
"Keep it there, you'll get the bipartisan majority" to win passage, he said.