Democrats and gun control advocates renewed their long-dormant push for limits on gun sales, building pressure on President Barack Obama to take a forceful stand on the subject.
Senator Dianne Feinstein, a California Democrat and senior member of the Judiciary Committee, said on ABC's "This Week" she'll intensify her push to renew an expired assault-weapons ban, which so far has failed to win political support in Congress. Senate Majority Whip Dick Durbin promised hearings.
Twenty children and six adults were shot to death on Dec. 14 by a man with an assault rifle at Sandy Hook Elementary School in Newtown, Connecticut. The suspect, Adam Lanza, 20, killed himself at the school with one of the two handguns he also was carrying. He shot his mother, Nancy, earlier at their nearby home, Connecticut state police said.
New York City Mayor Michael Bloomberg, an independent, criticized Democrat Obama for failing to act on an assault weapons ban and other firearm restrictions.
"It's time for the president to stand up and lead," Bloomberg said on NBC's "Meet the Press" program. "His job is not just to be well-meaning. His job is to perform and to protect the American public."
Obama, speaking yesterday at a memorial vigil in Newtown, said that while there is no single solution to the complex problem of violence in US society, "that can't be an excuse for inaction." Without offering a prescription, he vowed to do everything in his power to begin the search for an answer.
"We can't accept events like this as routine," he said.
Bloomberg, co-chairman of Mayors Against Illegal Guns, urged Congress to renew the 1994 ban on semi-automatic firearms that expired in 2004. He called for improved databases to trace gun ownership, stricter enforcement of gun trafficking and more laws to prevent sales to criminals.
"We don't need people carrying guns in public places," Bloomberg said on NBC. "That's not what the founding fathers had in mind. Quite the contrary, it makes us have a much more dangerous society."
It was the nation's second-deadliest school shooting, after a 2007 rampage on the Blacksburg campus of Virginia Polytechnic Institute and State University, where 33 people died.
Lanza used his mother's legally obtained guns, including an assault rifle, according to Connecticut's Democratic Governor Dan Malloy. Lanza "shot his way into the building," Malloy said on CNN's "State of the Union" program. "These are assault weapons. You don't hunt deer with these things."
Durbin, an Illinois Democrat who heads the Judiciary Committee's panel on the constitution and civil rights, said he will hold hearings on the constitutional question of gun rights early next year.
"Why would anyone, even Nancy Lanza, need a military assault weapon?" Durbin said on "Fox News Sunday."
The US experienced at least seven mass murders -- the killings of at least four people in one incident -- this year. Those incidents claimed at least 65 lives.
"I think we could be at a tipping point," Senator Charles Schumer of New York, the Senate's third-ranking Democrat, said on CBS's "Face the Nation" program. "The public will not accept as a new normal one of these incidents every month."
Speaking on "Fox News Sunday," retiring Senator Joe Lieberman, a Connecticut independent who ran on a gun control platform as Vice President Al Gore's Democratic running mate in the 2000 presidential election, called for a national commission to examine gun laws, the nation's mental health system and violence in video games and other entertainment.
During the 2000 campaign, Gore and Lieberman argued for "common-sense gun-safety measures," a position that cost them rural votes and helped give a narrow victory to Republican George W. Bush.
Many Republicans and Democrats oppose gun regulation, citing the Second Amendment to the US Constitution. Allowing more Americans to carry weapons is one way to limit casualties in mass shootings, said Representative Louis Gohmert, a Texas Republican.
He cited the "heroic stories" of Sandy Hook principal Dawn Hochsprung trying, and failing, to protect her pupils.
"I wish to God she had had an M4 in her office, locked up, so when she heard gunfire, she pulls it out," Gohmert said on the "Fox News Sunday" program. "She didn't have to lunge heroically with nothing in her hands, but she takes him out, takes his head off before he can kill those precious kids."
A semi-automatic Bushmaster assault rifle, similar to the M4 carbine used by the US military, was used in most of the school killings, according to Connecticut State Police.
"Every mass killing of more than three people in recent history has been in a place where guns were prohibited, except for one" Gohmert said. "They chose this place. They know no one will be armed."
Feinstein sponsored the 1994 assault weapons ban, which prohibited the sale of certain guns with high-capacity magazines that allow them to re-load automatically after being fired. Fully automatic weapons, which fire multiple rounds with a single pull of the trigger, continue to be regulated under federal law. The Feinstein measure, which applied to firearms manufactured after the law's enactment, expired in 2004.
Since then, Congress has enacted no major firearms regulations other than a law aimed at improving state reporting for federal background checks on gun purchasers.
The dearth of new gun laws reflects the political influence of the National Rifle Association, said Sanford Levinson, a constitutional law professor at University of Texas in Austin.
"The NRA has sufficient control over the Republican Party and the Democratic Party is, for good reason, scared stiff to go out on a limb on this issue," Levinson said. "There is absolutely no chance whatsoever of bipartisan gun control legislation."
The NRA declined to comment on the school shooting "until the facts are thoroughly known," according to a statement released by its communications office.