(CBS News) In the aftermath of last month's shooting in Colorado, in which graduate-school dropout James Holmes allegedly opened fire on a theater full of moviegoers with four legally purchased guns, killing 12 people and wounding 58 more, it seemed unlikely that politicians would embrace a serious conversation about gun laws. Gun control has long been seen as a politically toxic issue for Republicans and Democrats alike, and in a Congress defined by its bitterly partisan nature, the possibility of passing stricter gun laws is seen as a non-starter.
On Sunday, however, mass gun violence broke out in America for the second time in about two weeks, when a gunman opened fire in and outside of a Sikh temple in Wisconsin, killing six people before being fatally shot himself. The gun used in the attacks, a 9 mm pistol, was purchased legally "relatively recently" by the suspect at a local gun shop, according to CBS News source.
On the same day, three victims from the 2011 Tucson shootings, in which then-Rep. Gabrielle Giffords, D-Ariz., was shot in the head and six others were killed, appeared in an ad demanding that President Obama and Mitt Romney outline a plan to reduce gun violence in the United States.
Now, despite a widespread reticence among members of Congress and political candidates to raise the issue of gun control on the campaign trail, some candidates and Congress members are renewing the calls for new gun control measures.
"Our hearts are heavy today with the weight of another shooting massacre that has shattered a peaceful community, and our thoughts are with those in mourning and others still recovering from their wounds," said Sen. Frank Lautenberg, D-N.J., in a statement. "We send a message of sympathy to the family and friends of the victims and ask colleagues in government and Americans across the country to join together and redouble our efforts to prevent gun violence."
It's an issue that has gained little traction in Congress in recent years, even among Democrats.
"The votes aren't there for gun control," said House Minority Leader Nancy Pelosi, in an interview with the Huffington Post. "We certainly aren't going to be able to do it in this Congress, and I don't know that we would be able to do it in a Democratic Congress because it takes a lot of votes to go down that path."
But not everyone is content with that response.
Rep. Diana Degette, a Democrat who represents Colorado's first district, argues that change isn't impossible, but that the conversation needs to change.
"I really think people need to think about talking about this in a different way," she told CBSNews.com.
Degette, whose district is near Aurora, Colorado, where last month's shootings took place, said that she accepts the premise that the Second Amendment grants Americans a right to bear arms. The conversation shouldn't be about "should we have guns, or shouldn't we have guns," but rather, what kinds of guns should civilians be permitted to carry?
"What I really think is that you need to look at these assault rifles that are only intended to kill people, and these multiple ammunition magazine cartridges. If that magazine hadn't jammed at 60 rounds, [the Aurora shooter] probably could have shot everybody in the theater... People are getting angry. They're getting angry at this obviously deranged shooter, but they're also getting angry that we don't have laws that would better protect them against these types of weapons."
Parsing public opinions
According to a recent Pew Poll, conducted after the Aurora shooting, Americans are divided when it comes to prioritizing the right to own guns vs. controlling gun ownership. In April of 2012, 45 percent of voters said they thought it was more important to control gun ownership, while 49 percent said it was more important to protect the right to own guns. In the July poll, 47 percent prioritized controlling gun ownership, and 46 percent selected the right to own guns.
The same survey showed that most Americans - 67 percent - believe the Aurora shooting was the isolated act of a troubled individual, while only 24 percent said it reflected broader social problems in America. The disparity between those numbers has increased since both 2011, after the Tucson shootings, and in 2007, when a gunman opened fire at Virginia Tech University, killing 32 people.
A Gallup poll from October 2011, meanwhile, showed an all-time low of 26 percent support for a legal ban on handgun possession.
"Our recent polls seem to suggest that the public is more divided about gun laws, and there's more support for protecting gun owners' rights than there was previously," said Scott Keeter, Pew Research Center's director of survey research.
Keeter says there's no clear statistical indicator as to the source of this shift in public opinion, but that one possible reason could be a disparity in the force with which both sides are debating the issue. If gun rights advocates are making a much more vocal case for their argument than are gun control advocates, he says, it's plausible that the public would be swayed by one side more than the other.
"If right now you're not hearing much of a pro-gun control argument from leaders in the Democratic Party, for example, then maybe the public is being more persuaded by the arguments you're hearing from the other side."
The Power of the NRA: Fact or Fiction?
Not all Democrats are silent on the issue of gun control: Leading advocates include Carolyn McCarthy, a New York congresswoman, whose husband was killed and son severely injured in an incident of gun violence in the 1990s, Lautenberg, and New York Sen. Chuck Schumer, all Democrats and all of whom have recently attempted to introduce new gun control legislation into Congress. New York City Mayor Michael Bloomberg, a Republican-turned-independent, is also a staunch supporter of stricter gun laws, and has since the Aurora shootings been outspoken about his belief that gun violence needs to be addressed.
But most of the nation's most active gun control advocates represent liberal constituencies, which tend to be more supportive of stronger gun laws. Moreover, Bloomberg is not currently running for office, and neither Schumer nor Lautenberg are up for re-election in 2012. According to the New York Times' projection model, McCarthy, who represents New York's 4th District, in Long Island, has a 97.5 percent chance of reclaiming her seat in 2012.
In states with bigger pro-gun communities, and in elections that are more tightly contested, advocating gun control is seen as a major risk for political candidates - particularly given the perceived power of the National Rifle Association (NRA), the influential gun rights lobbying group.
"I think it's telling that candidates in closely-contested races don't want to take on the NRA," said Adam Winkler, a constitutional law professor at the University of California - Los Angeles. "Candidates are just not really willing to take a stand in favor of gun control on Election Day."
With most voters concerned primarily about the economy, gun control is not a top talking point on the campaign trail. Theoretically, however, candidates who even support stricter gun laws in the abstract could feel the impact of the NRA's power: The organization grades candidates based on their positions on gun rights, and endorses candidates based on those grades. The organization also targets candidates who score poorly.
According to Winkler, there's little advantage to supporting gun control laws, because few people would likely vote for a candidate solely on that issue.
"Supporting gun control does not translate into votes on election day," he said. "I think the key here is that gun control is not on the top of very many people's agendas, so supporting it doesn't gain you a lot of votes - but it can lose you a lot of votes."
For years, gun control advocates have questioned the power of the NRA, contending the perception that the organization has the power to singlehandedly take down a candidate is overblown. According to OpenSecrets.org, the NRA has spent just $1.5 million on lobbying in 2012 thus far - far less than many other groups, who are funneling millions into individual primary races alone.
Meanwhile, a handful of surveys show that many Americans favor stricter gun laws in some capacity, particularly when presented with specific proposals as to what those restrictions would be. A CBS/New York Times
Gun control advocacy groups like the Brady Campaign to Prevent Gun Violence say that in suburban areas, particularly among women, touting support for stricter gun laws could actually be an advantage for Democrats. The Brady Campaign also argues that the myth of the NRA is the most powerful element of the group's strategic advantage -- and that debunking that myth could help pave the road toward implementing new policies.
Changing the conversation
Degette says she's unfazed by the NRA despite serving in a state with a long history of support for Second Amendment rights, but that it's important to have a nuanced conversation when discussing gun control in states like Colorado.
"I've been in elected office for 20 years and the NRA has been mad at me for 20 of them. It's never adversely affected my career," she said. "But I think you have to talk about the issue in a way that's responsible and sensible, and not overly broad or oversimplified in its implications in either direction."
She and many other people who support some version of stricter gun laws - such as the renewal of the Assault Weapons Ban, which passed in 1994 but was not renewed - argue it's important to distinguish between supporting restrictions on certain types of weapons and on stripping citizens of the right to bear arms in general.
"I think the NRA is one of the most powerful lobbying organizations in Washington, but I think that if a candidate talks about semi-automatic weapons like assault weapons, and multiple round ammunition cartridges, and things that go far, far beyond what I think the Second Amendment guarantees, I think it will really resonate," said Degette. "It'll resonate with moms; it will resonate with the vast majority of Americans, who don't believe there's an unlimited right of Americans to carry unlimited weapons."
Continued resistance from the right
Many gun-rights advocates beg to differ.
"As far as gun laws go, I'm pretty much for just about all kinds of guns," said Samuel Wurzelbacher, also known as "Joe the Plumber," who is challenging longtime Democratic Rep. Marcy Kaptur for her Ohio congressional seat.
Wurzelbacher, like many gun rights activists, argues that stronger gun control laws would not have prevented rampages like that in Aurora, and that restricting gun rights prevents brave Americans from trying to stop violent offenders in the act.
"If someone's taking innocent lives, someone should be able to step up and stop that situation," Wurzelbacher told CBSNews.com.
Chris Shays, a former Republican congressman running for Senate in Connecticut and a former advocate of the Federal Assault Weapons Ban, argues that the ban didn't work the first time around and that America needs to start looking for different types of solutions.
Shays said he did think there were legitimate concerns about how guns are bought and sold and gun shows, where it is possible in some states for unlicensed dealers to sell firearms without conducting criminal background checks. But, he emphasized, "if we really are sincere about coming to grips with what happened in Aurora and what has happened in other places, we have to have a good talk about what the media does, what TVs do."
"The media talks about the independence of a free press and the NRA talks about the rights of the Second Amendment. They both have very legitimate claims," he said.
From Wurzelbacher's perspective, the value of Second Amendment rights is simple: "It's a very scary world out there, but I feel much safer when I have a 45 [millimeter gun] in my hand."
He added: "An armed populous, I believe, is a safe populous."