Last January, Representative Gabrielle Giffords was shot in Arizona during a public meeting with constituents. In the wake of the shooting, the media began a national dialogue about how violent political rhetoric can spark actual violence.

After reading about GOP front-runner Herman Cain’s immigration “policy,” I think it’s time we have that discussion again. In a campaign speech last weekend in Tennessee, Cain proposed an electric fence running the length of the U.S. Mexico border with a voltage strong enough to kill anyone who attempts to cross. “It’s going to be 20 feet high,” he said. “It’s going to have barbed wire on the top. It’s going to be electrified. And there’s going to be a sign on the other side saying ‘It will kill you – Warning.'” Cain also proposed positioning military troops along the border “with real guns and real bullets.” According to press reports, the audience cheered loudly.

Cain’s remarks, and the audience’s cheers, are a pretty accurate illustration of how vitriolic and hate-filled our country’s immigration debate has become. Essentially, Cain is calling for the death penalty for illegal border crossing. Illegal crossing, for first time offenders, is only a misdemeanor under federal law.

Unfortunately, we’ve heard worse. Like Kansas State Representative Virgil Peck Jr.’s comments that “If shooting . . . immigrating feral hogs works, maybe we have found a solution to our illegal immigration problem.” And Representative Mo Brooks’ (R. AL) comment that he would do “anything short of shooting” illegal immigrants to keep them out of the country. And Alabama State Senator Scott Beason’s comment that it’s time to “empty the clip” when dealing with illegal immigration.

In the days following the attack against Representative Giffords, Sarah Palin was criticized for using similar gun rhetoric like “don’t retreat…reload,” in her campaign materials. While the American public ultimately disagreed on whether violent rhetoric incited the attack against Giffords, there was at least some discussion of the idea that language has consequences.

There is plenty of evidence to suggest that violent anti-immigrant rhetoric has life-threatening consequences for immigrants – both legal and illegal, since vigilantes don’t often ask to see papers. The FBI reported that hate crimes against Latinos and Latinas increased by forty percent between 2003 and 2007, the period when political candidates became especially vocal about anti-immigration platforms.

An article in yesterday’s Huffington Post points out some of the most egregious examples. It describes the attack against Alex and Jose Cauich, Mexican nationals who were assaulted outside a bar in San Francisco while their attackers yelled “run like you ran across the border.”

The article also points out that non-immigrants of Mexican descent are being targeted, too. Juan Varela, nine year-old Brisenia Flores and her father were all murdered by anti-immigrant extremists, and all three were American-born U.S. citizens.

The sentiment is spreading to schools, and last week, Assistant Attorney General Tom Perez reported seeing an increase of anti-immigrant bullying in Alabama schools.

Border protection and immigration reform are hot-button issues, and I’m sure we’ll hear much more from the campaign trial. But there’s a difference between policies (and politicians) that treat immigrants as problems and policies that treat them as people. GOP candidate Rick Perry, made this point when he called for an “intellectually appropriate discussion about immigration reform.” Perry, who has been the governor of a border state for more than a decade, has proposed a technological approach, using border cameras and Predator drones to send information to local law enforcement.

We need solutions like those Perry has proposed, and we certainly need reform. But most of all, we need a civil dialogue. If the tone of debate continues to devolve into gun rhetoric, death threats, and calls for violence, these speeches may warrant the same warning sign as Cain’s electric fence.