President Barack Obama urged U.S. lawmakers to remember the children killed by gun violence and not weaken in the face of a powerful gun lobby as he reached out to moderate members of his own party before a Senate vote on gun controls expected next month.
His comments Thursday came as new details were revealed in the December school shooting that left 20 young children dead and brought gun safety back into the national spotlight.
Obama, flanked by grim-faced mothers who have lost children to guns as recently as last month, said Washington must do something.
"Shame on us if we've forgotten," Obama said. "I haven't forgotten those kids."
He said the upcoming vote is the best chance in more than a decade to reduce gun violence.
The gun control legislation faces an uncertain future, even though more than 80 percent of Americans in polling say they support expanded background checks in gun purchases, which appears to be the most popular of the package of gun measures that Obama proposed just a month after the December shooting.
The young gunman in that shooting used a high-powered rifle legally purchased by his mother, whom he also shot to death. Warrants released Thursday show that on the day of the massacre, Adam Lanza also took two loaded handguns to the school. A fourth gun, a loaded 12-gauge Saiga shotgun, was found in the passenger compartment of his car, along with 70 shotgun rounds.
Obama encouraged Americans, especially gun owners, to press lawmakers to "turn that heartbreak into something real."
Among the forces opposing gun control is the National Rifle Association, a gun advocacy group that can put pressure on senators seeking re-election should they vote for restrictions the NRA opposes.
"We have a politically savvy and a loyal voting bloc, and the politicians know that," said Andrew Arulanandam, spokesman for the NRA, which claims nearly 5 million paying members.
The heart of the Senate gun bill will be expanded requirements for federal background checks for gun buyers.
Senate Democratic leader Harry Reid has said there are not enough votes to approve a ban on assault weapons, while prospects are uncertain for a prohibition on large-capacity ammunition magazines. The gun bill also increases penalties for illegal gun sales.
Today, the background checks apply only to sales by the nation's roughly 55,000 federally licensed gun dealers. Not covered are private transactions like those at gun shows and online.
Expanding background checks to include gun show sales got 84 percent support in an Associated Press-GfK poll earlier this year. Near-universal background checks have received similar or stronger support in other national polls.