People attend a candlelight vigil for the victims of the Aug. 5 shooting at the Sikh Temple of Wisconsin in Oak Creek, Wis., on Aug. 7.
In 1990, 78 percent of Americans supported tougher restrictions on gun sales, according to a Gallup poll. A decade later, that number fell to 44 percent.
Part of the reason has to do with how the debate has been framed: one between those who want to ban all guns and those who want to protect the right to own them.
The reality is far more complex. Private gun ownership is a fact of life in the U.S. The country tops the charts worldwide in terms of civilian gun ownership. A 2007 study from the United Nations Office on Drugs and Crime [PDF] reported there were 270 million private firearms in the U.S.
The question is how to keep them away from people who perpetrate crimes like the recent shootings in Aurora, Colo., and in Oak Creek, Wis. That's the tricky part - partially because getting a gun in the U.S. can be fairly easy.
At the Blue Ridge Arsenal in Virginia, sales rep Mark Warner says the process can take only about 25 minutes. You pick any gun, fill out a form and wait for approval.
"If you're a law-abiding citizen and you don't have a criminal record and the computer likes you in Richmond, you're done in 15-25 minutes," he says.
And that's if you buy it in a shop.
Dan Gross, president of the Brady Campaign to Prevent Gun Violence, says 40 percent of legally sold guns are sold without a background check. That 40 percent includes the guns sold at gun shows or through classified ads, where legal loopholes don't require background checks.
"Every day in our nation, 32 Americans are killed by guns," Gross says.
He argues that a few simple changes - tighter background checks, a ban on certain types of weapons - could all make the difference.
It's been done before. In the early 1990s, the Brady Handgun Violence Protection Act, or the "Brady Bill," introduced background checks. Then-President Clinton signed it into law in 1993. From 1994 to 2004, the sale of assault weapons was banned.
How To Tackle Crime Rates
But is there a link between gun restrictions and fewer murders?
Paul Barrett, author of a book on the history of the famous Glock handgun, says the answer is no.
"Criminologists have studied it, and the consensus is that those laws simply did not have a statistically meaningful effect on crime rates," he tells Guy Raz, weekends on All Things Considered.
Barrett says making slight changes to existing laws won't bring down the homicide rate. The equation of "more guns equal more crime" just doesn't add up, he says.
"There's a relationship between the presence of guns and the lethality of crime, but there is not a cause-and-effect, simple formula that will solve crime problems by simply regulating, in slightly different ways, how easily you can acquire a gun," he says.
Gun-control advocates point to the shootings in Colorado and Milwaukee as justification for stricter laws. But Barrett argues that's not the nation's biggest gun issue.
"We fixate, understandably, on the aberrational mass-shooting events, but they're actually not our main social problem," he says. "Our main social problem is the overall gun homicide rate."
The Political Calculus
Still, neither the overall homicide rate nor the recent atrocities have spurred real political action. Barrett says President Obama is probably just taking history into account and deciding that "it is not worth the political punishment to tinker with gun laws."
The first lesson would be the presidential election in 2000. Then-candidate Al Gore was targeted by the National Rifle Association in key sates because he had been vice president when Clinton signed the assault-weapons ban.
The result? Gore lost in states he should have won: his home state of Tennessee, Clinton's home state of Arkansas and West Virginia. Barrett says Gore's losses were due "in large part" because of the gun-rights activism.
Another example of political backlash is the 1994 turnover in the House. The Republican sweep in that election followed the enactment of the assault-weapons ban. Barrett says Clinton himself attributed the election at least in large part to the gun laws.
Barrett breaks down the political calculation for like this: "a huge downside risk, a marginal upside potential to please people who are going to vote for you anyway."
"There is just not a lot of popular demand for stricter gun control," he says. "The public opinion polls tell you that, and I think Barack Obama and his advisers can read those polls."