Last night, in his final State of the Union address, President Obama made another call -- albeit a brief one -- to pass new measures to prevent gun violence.

"I'll keep pushing for ... protecting our kids from gun violence," he said, as an chair sat empty beside First Lady Michelle Obama symbolizing a victim of gun violence.

It was the latest in a series of statements by the president drawing attention to the unusual level of gun violence in the United States and a series of executive actions he's taking in an effort to reduce it, after legislative proposals failed in 2013.

An interesting fact about his proposals is he has admitted they might have only a modest impact -- raising the question, for proponents of gun control, of whether these policies would be enough. Obama has rejected the idea of confiscating Americans’ guns, but the evidence suggests that it is likely the only policy that would dramatically reduce gun violence in the United States.

In a town-hall meeting broadcast on CNN last week, the president noted that more than 30,000 Americans die annually from gunshot wounds. That stat comes from the Centers for Disease Control and Prevention.

“We're not going to eliminate gun violence, but we will lessen it,” Obama said. “If we take that number from 30,000 down to, let's say, 28,000, that's 2,000 families who don't have to go through what the families at Newtown or San Bernardino or Charleston went through."

Obama believes his policies can save thousands of lives a year, but acknowledges that gun shots would still kill tens of thousands of Americans annually. That intense level of firearms violence is one that Obama and other gun-control advocates might be forced to tolerate unless they push measures that are more invasive than background checks.

In Connecticut and Missouri, the data suggests laws requiring background checks to buy firearms prevented some homicides -- about 14 percent of killings in Missouri, and about 40 percent in Connecticut. The research is promising. Gun violence is so common in the United States that reducing its frequency by just a few percent would save thousands of lives.

Yet it is hard to know whether similar laws would have the same effect in other states. The states that enact stricter gun-control laws tend to be the ones in which there are also fewer guns and therefore fewer gun owners to agitate for gun rights. It isn't always clear whether a decrease in gun deaths in a particular state is due to a new law or a lack of guns.

It's also unclear whether such laws do anything to prevent suicides is unclear. As Obama noted, a large majority of gun deaths are suicides.

Shannon Watts, the founder of the gun-control advocacy group Moms Demand Action for Gun Sense in America, believes that major reductions in the rate of gun violence are possible. Since the massacre at Newtown, Conn. in 2012, six states have required background checks for all gun purchases, a measure that failed in Congress. Watts is optimistic that the preliminary data from these states shows reductions in gun deaths.

She also blamed Congress and the National Rifle Association for opposing any action on the issue at all -- and for obstructing research on guns that could identify policies that could potentially save lives. The CDC has not funded research on the issue, fearing that lawmakers who support gun rights would reduce the agency's budget in retaliation.

"Saving 2,000 lives, even though 30,000 are shot and killed a year, is better than what Congress wanted to do, which was to do nothing," Watts said.

"There is no silver bullet," she added, blaming the gun-rights lobby for preventing progress on new safety components in guns and on better enforcement of existing trafficking laws.

The White House declined to provide immediate comment.

One policy that proved remarkably effective in preventing suicides was Australia’s mandatory buy-back scheme. The country required owners of certain weapons to forfeit them to the government in exchange for cash following a gun massacre on the island of Tasmania in 1996. The government confiscated about one in five civilian firearms, and the rate of suicides declined by 80 percent.

Obama, however, has said he believes Americans have a right to own guns . Polls show that while support for stricter gun-control policies has increased this year, a majority still opposes a ban on handguns. For its part, the Supreme Court has declared that the Second Amendment permits Americans to keep a loaded handgun at home for self-defense.

“I respect the Second Amendment. I respect the right to bear arms,” the president said on CNN. “I respect people who want a gun for self-protection.”

Correction: An earlier version of this item wrongly implied that Shannon Watts criticized Republicans in Congress for obstructing gun-control initiatives. Watts's criticism of congressional inaction on the issue encompasses both parties.

Additionally, the earlier version omitted the full name of Watts's organization. It is "Moms Demand Action for Gun Sense in America," not "Moms Demand Action for Gun Sense."