By Roger Runningen and Lisa Lerer
ALLENWOOD — WASHINGTON — President Barack Obama, with families of victims of the Connecticut school shooting tragedy at his side, Thursday pressed the Senate to pass gun-control legislation next month and urged lawmakers to resist any weakening of resolve.
"This is our best chance in more than a decade to take common-sense steps that will save lives," Obama said at a White House event, where he was joined by law enforcement officials, victims of gun violence and their families. "We have an obligation to try."
Gun controls proposed after the Dec. 14 mass killing at a Newtown, Conn., elementary school face an increasingly thorny path to passage in Congress. The White House event came as gun control supporters organized more than 120 rallies across the country Thursday, in an effort to increase pressure on lawmakers.
"Shame on us if we've forgotten" the grief of Newtown and the other mass slayings, Obama said. "There's absolutely no reason that we can't get this done."
Senate Democratic Leader Harry Reid plans to call for votes next month on gun legislation that includes expanded background checks and tougher penalties for gun trafficking. The bill will not include limits on military-style assault weapons and high- capacity magazines — proposals backed by the White House and anti-gun violence advocates. Those are to be offered as amendments, which Reid says lack support to pass.
Public support for tougher gun control laws has fallen by 10 percent, down to 47 percent from a peak of 57 percent just after the shootings, according to a March 26 poll by CBS News. Thirty-nine percent of those surveyed said they want laws kept as they are, and another 11 percent want them made less strict, CBS said.
The telephone survey March 20-24 of 1,181 adults nationwide had a margin of error of plus or minus three percentage points.
In a conference call Wednesday with mayors and other supporters of gun control, Vice President Joe Biden said the White House will continue to fight for together gun control measures beyond the Senate votes.
"That doesn't mean this is the end of the process," Biden said. "This is the beginning of the process."
A coalition of mayors also released its first television ad, featuring family members of those killed in the Connecticut school shootings calling on lawmakers to support "comprehensive and enforceable background checks."
"We cannot afford to wait for another tragedy. It's long past time for elected officials to listen to their constituents and pass reforms," said Michael R. Bloomberg, mayor of New York and co-chairman of Mayors Against Illegal Guns.
Bloomberg announced March 25 a $12 million television ad campaign running in 13 states that urges senators to support legislation expanding background checks for gun purchases. The mayor is founder and majority owner of Bloomberg LP, the parent company of Bloomberg News.
Wayne LaPierre, chief executive officer of the National Rifle Association, said Bloomberg's ad campaign will fail to persuade the public to support gun restrictions.
"They sure don't want him telling what self-defense firearms to own," LaPierre said on the same NBC program. "And he can't buy America."
LaPierre called universal checks "a dishonest premise. Criminals aren't going to be checked. They're not going to do this."
Josh Earnest, a White House spokesman, said Wednesday that a Senate vote on whether to ban military-style assault weapons represents progress, given how hard the president has pushed for tougher restrictions.
"I can't stand here and guarantee that it's going to pass, but it is a question that 100 senators are going to ask themselves when they wake up in the morning and look themselves in the mirror about whether or not they are going to — about which side they're going to be on when it comes to voting on a ban on military-style assault weapons," he said.