WASHINGTON — President Obama implored Congress on Wednesday to ban the sale of military-style assault weapons and to institute universal background checks for all gun buyers, as he outlined a broad proposal to prevent more mass shootings and attempted to rally public support for the effort.
Obama’s proposals came on the same day as Governor Deval Patrick unveiled his own plans to tighten what are already some of the nation’s toughest gun control laws. Under Patrick’s proposal, background checks would be required at gun shows; firearm magazines would be reduced to a maximum of seven rounds; and gun purchases would be limited to one a month for licensed buyers.
The day’s actions illustrated how gun control is moving forward on three tracks: Obama’s use of his executive powers to enhance gun laws; calls for congressional action that face stiff resistance; and states attempting to craft their own measures.
“This is our first task as a society, keeping our children safe,” Obama said during an emotional ceremony in an auditorium next to the White House. “This is how we will be judged.”
The gun control debate has flared since the Dec. 14 shooting at Sandy Hook Elementary School in Newtown, Conn., that killed 20 young students and six educators. Obama noted that more than 900 Americans had been killed by guns in the month since those shootings.
Following the ceremony, Obama signed 23 executive actions that took effect immediately and did not require congressional approval. Those measures will increase enforcement of existing laws, allow federal agencies to research gun violence, and encourage states to supply more information for federal background checks. But the more sweeping changes will need congressional action, and some Republicans swiftly rejected Obama’s call for an assault weapons ban.
“Nothing the president is proposing would have stopped the massacre at Sandy Hook,” said Senator Marco Rubio, a Florida Republican. “President Obama is targeting the Second Amendment rights of law-abiding citizens instead of seriously addressing the real underlying causes of such violence.”
Advocates for the Obama proposal have said it might have made a difference in the case of Sandy Hook because it would have limited the amount of ammunition that could be loaded into a semiautomatic rifle at one time.
In a sign of how bitter the debate is likely to be, on Wednesday morning the National Rifle Association released an online advertisement calling Obama an “elitist hypocrite” because his two daughters are protected by gun-carrying members of the Secret Service.
“Are the president’s kids more important than yours?” the ad asks, referencing his daughters Sasha, 11, and Malia, 14, without showing their images.
White House Press Secretary Jay Carney called the ad “repugnant and cowardly,” and several hours later Obama tried to answer to such tactics.
‘‘Behind the scenes, they’ll do everything they can to block any commonsense reform and make sure nothing changes whatsoever,’’ Obama said. ‘‘The only way we will be able to change is if their audience, their constituents, their membership says this time must be different, that this time we must do something to protect our communities and our kids.’’
White House officials said their proposal would cost $500 million to implement. Obama also called for additional safeguards in schools, in part by putting an additional 1,000 police officers and counselors in schools. The NRA, by contrast, has called for armed guards in all schools.
During the announcement, Obama was joined by four young children who wrote to him in the aftermath of the Newtown shootings. One urged changes, another said she felt bad for the parents of the children who died, and a third said she was scared such a shooting could happen again.
In the audience were gun control advocates, members of Obama’s Cabinet, and family members from the Sandy Hook shooting. At one point, Obama spoke of a child’s painting that now hangs in his private study. The painting was made by a girl who was killed in Newtown; the girl’s father gave the picture to the president.
The White House believes that the nation’s conscience was so shaken by what happened at Sandy Hook that politicians will have no choice but to act. Obama urged Americans to contact members of Congress, something that he plans to continue doing to exact pressure for action.
“Ask them what’s more important — doing whatever it takes to get an A grade from the gun lobby that funds their campaigns, or giving parents some peace of mind when they drop their child off for first grade?” Obama said.
The recommendations came from a task force that was spearheaded by Vice President Joe Biden, who as a US senator in 1994 led the last major effort to address gun control.
Obama’s plan would enhance background checks by requiring all those who buy a gun to be checked for things like a history of mental health issues. Right now, those who purchase guns from licensed dealers have to undergo such checks, but those who buy them from unlicensed dealers do not. By some measurements, about 40 percent of guns are purchased without the buyer going through a background check.
The most controversial proposal is one that would ban certain assault rifles, and limit gun magazines to 10 rounds. Such a ban was put in place in 1994 but it was not renewed a decade later. On Wednesday, Obama noted that President Ronald Reagan — whom he called “one of the staunchest defenders of the Second Amendment” — supported the assault weapons ban in 1994.
Republicans have voiced support for some aspects of Obama’s proposal — including the enhanced background checks — but have been largely opposed to an assault weapons ban.
As Washington continues to grapple with the issue, several states, including Massachusetts, are crafting their own response.
“The time for action is now,” Patrick said in a statement. “All of us must pull in the same direction to bring about real change in this state and across the country.”
The governor’s plan also would require state courts to share mental-health records with a national registry used for background checks. Patrick is also seeking an additional $5 million for enhanced mental-health treatment and training programs to increase public safety and provide better access to services.
The money would bolster mobile teams that respond quickly to individuals in crisis; train teachers and school administrators to spot and address mental illnesses; and double the funding for crisis-intervention training for police and other first responders.
The governor also is seeking new ways for police and prosecutors to quickly respond to — and punish — anyone caught with weapons on school grounds. The plan would give authorities the right to arrest without a warrant “in order to quickly diffuse a dangerous situation on school property.’’
Patrick’s proposals are part of growing momentum on Beacon Hill to pass stricter gun control measures in the aftermath of the Newtown massacre. House Speaker Robert DeLeo, who has said he expects such legislation to pass, is creating an independent panel to study the state’s laws, compare them with others nationally, and suggest improvements.
The state currently has the nation’s lowest firearm fatality rate, at 3.1 per 100,000 people, according to John Rosenthal, the founder of Stop Handgun Violence, an advocacy group based in Newton. The US average is 10.6.
Matt Viser can be reached at email@example.com.