Last week, Republican presidential candidate Herman Cain vowed that, if he was elected president, he would build a 20-foot-high electrified fence on the border with Mexico with a sign alongside it that would read: “Crossing the border illegally has a price; it will kill you.”

Neither Rick Perry nor Mitt Romney can claim conservative purity on illegal immigration — and now both must deal with it. Illegal immigration has emerged as a defining issue with remarkable staying power in a GOP presidential race that was expected to be primarily focused on the nation’s struggling economy.

In the debate over immigration among the Republican presidential candidates, Representative Michele Bachmann of Minnesota signed a pledge last week to build double-fencing the entire length of the 2,000-mile border with Mexico.

The Obama administration soon will begin its systematic review of the approximately 300,000 pending deportation cases, separating “high priority” cases involving criminals it wants to deport from “low priority” cases it will drop, Homeland Security Secretary Janet Napolitano told Congress Wednesday.

The American Civil Liberties Union has released government documents containing 185 allegations of sexual abuse against female immigration detainees in federal detention centers since 2007. The documents, obtained under the Freedom of Information Act, include detailed narratives by three women who describe sexual assaults by guards while the detainees were being transported in prison vans.

Last night’s Republican presidential debate, as expected, featured more fireworks over the issue of immigration and turned into a contest of who could talk tougher on the issue. In an attempt to defend his past household employment of an undocumented worker, Governor Mitt Romney (R-MA) explained why he insisted his workforce be legal by saying, “I’m running for office for Pete’s sake, I can’t have illegals.”

The sprint to the right by the Republican Presidential candidates, which was on display again at last night’s debate in Las Vegas, should be helpful to President Obama’s reelection. It should be. But, the Department of Homeland Security (DHS) continues to undercut his Latino outreach efforts.

Last weekend in Tennessee, Herman Cain boasted that as President, he’d build a fence along the U.S.-Mexican border “20-feet high, with barbed wire, and electrified.” The crowd applauded, and in an interview a day later, Cain shrugged the whole thing off as “a joke.” He might come to regret being so cavalier about immigration, which ranks chief among Latino voters’ policy concerns.

Rick Perry’s most pointed attack against Mitt Romney in Tuesday night’s debate concerned an immigration matter that came to light when Mr. Romney was campaigning for president four years ago.

A leading House Democrat is taking GOP presidential contender Herman Cain to task for suggesting an electric border fence would be the country’s best defense against illegal immigrants. Rep. Silvestre Reyes (D-Texas) accused Cain on Tuesday of “spewing hate” and inciting violence without offering any real solution to the illegal immigration issue.