Obama, in a speech to an African-American group Wednesday in New Orleans, embraced some degree of additional restrictions on guns. He acknowledged that not enough had been done to prevent weapons from getting into the hands of criminals and pledged to work with lawmakers from both parties to move forward on the matter.
Romney said in a television interview that changing the nation's laws would not prevent gun-related tragedies. But he mistakenly said many weapons used by the shooting suspect in Aurora, Colo., were obtained illegally, despite the fact that authorities allege that the firearms used to kill 12 people and injure dozens more were purchased legally.
Neither candidate strayed significantly in their remarks Wednesday from their previously held positions on gun violence. But their pointed comments revived a debate -- if perhaps only briefly -- that has steadily faded to the background in national politics and been virtually non-existent in the 2012 campaign.
The White House in particular has faced fresh questions since the shootings about whether Obama, a strong supporter of gun control as a senator from Illinois, would make an election-year push for stricter measures.
Following last year's killing of six people and the wounding of Rep. Gabrielle Giffords in Arizona, Obama called for steps to "keep those irresponsible, law-breaking few from getting their hands on a gun in the first place." But he has advanced no legislative proposals since then.
The White House blames the lack of legislation in part on congressional opposition and says Obama has used his executive powers to strengthen some gun control measures.
It's been more than a decade since gun control advocates had a realistic hope of getting the type of legislation they seek, despite predictions that each shocking outburst of violence would lead to action.
During remarks Wednesday night to the National Urban League, Obama acknowledged a national pattern of calling for tougher gun restrictions in the wake of violent crimes but not following through.
"Too often, those efforts are defeated by politics and by lobbying and eventually by the pull of our collective attention elsewhere," he said.
Obama called for stepped-up background checks for people who want to purchase guns and restrictions to keep mentally imbalanced individuals from buying weapons. Those steps, he said, "shouldn't be controversial. They should be common sense."
Still, Obama is unlikely to make a robust push for new gun control legislation while mired in a deadlocked campaign centered squarely on the economy.
Romney was pressed on gun control during an interview with NBC News in London, where he is attending the Olympics and kicking off a three-country foreign trip. The presumptive Republican nominee said changing laws won't "make all bad things go away."
Romney was asked about his tenure as Massachusetts governor, when he signed a bill that banned some assault-style weapons like the type the Colorado shooter is alleged to have used. At the time, Romney described such guns as "instruments of destruction with the sole purpose of hunting down and killing people."
Asked if he stood by those comments, Romney mentioned the Massachusetts ban but said he didn't think current laws needed to change.
"I don't happen to believe that America needs new gun laws. A lot of what this ... young man did was clearly against the law. But the fact that it was against the law did not prevent it from happening," Romney said.
Authorities have said the suspected Colorado shooter, James Holmes, methodically stockpiled weapons and explosives at work and home in recent months. He purchased thousands of rounds of ammunition and a shotgun, a semi-automatic rifle and two Glock pistols, authorities said.
On Friday, clad head to toe in combat gear, he allegedly burst into a midnight showing of "The Dark Knight Rises" at an Aurora, Colo., movie theater, tossed gas canisters into the crowd and opened fire.
The Colorado shootings also have brought fresh attention to the frequent incidents of gun violence that plague many American cities, including Obama's hometown of Chicago.
Obama addressed the nationwide troubles in front of the Urban League in part because African-Americans, who make up the bulk of the organization's membership, have been disproportionately affected by gun violence. While mass shootings like the one in Colorado receive widespread attention, Obama said roughly the same number of young people are killed in the U.S. by guns every day and a half.
"For every Columbine or Virginia Tech, there are dozens gunned down on the streets of Chicago and Atlanta, and here in New Orleans," he said. "For every Tucson or Aurora, there is daily heartbreak over young Americans shot in Milwaukee or Cleveland."
The president urged parents, neighbors and teachers to also play a role in helping end gun violence among young people.