Immigration debate intensifies in GOP race

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.

The heated clashes over illegal immigration between the two Republican presidential rivals in this week's debate, coupled with renewed calls for a fence along the U.S.-Mexico border by their opponents, made clear the issue isn't going away. It's a major fault line between Perry and Romney as they court a Republican primary electorate that generally takes a hardline view against people who are in the country illegally.

At every turn, Perry, the Texas governor, has been forced to defend his signing of a law that allowed some illegal immigrants to get in-state college tuition. And now Romney is having to answer for the fact that some groundskeepers who had worked on his lawn were in the country illegally.

"Mitt, you lose all of your standing from my perspective because you hired illegals in your home, and you knew about it for a year," Perry told the former Massachusetts governor at Tuesday's debate in Las Vegas. "And the idea that you stand here before us and talk about that you're strong on immigration is, on its face, the height of hypocrisy."

Romney countered, "Rick, I don't think that I've ever hired an illegal in my life" and challenged his rival to show him the facts.

It was a preview of what Republicans can expect to hear in the coming weeks as the Jan. 3 leadoff Iowa caucuses inch closer, with Romney and Perry emerging as the two candidates with the best chances of winning the nomination. They're arguably the only Republicans with the money and organization necessary to go the distance.

Even so and in hopes of gaining traction, their rivals are playing to the part of the GOP electorate that values a secure border with Mexico above all else when it comes to immigration policy.

In recent days, Minnesota Rep. Michele Bachmann of Minnesota has pledged to build two fences back to back along the 2,000-mile border. And businessman Herman Cain called for an electrified fence that could kill people trying to cross illegally.

For months now, immigration concerns have followed presidential contenders to town hall meetings from Nevada to Iowa to New Hampshire. And in some ways, immigration has shaped the increasingly bitter Republican nomination fight more than any other issue, particularly in a crowded field where the conservative candidates have more in common than not. And while conservative voters may be driving immigration chatter on the campaign trail, the candidates are stoking voter passions when given the opportunity.

"I'm not surprised that immigration is playing as big a role as it is," said Kevin Smith, a likely New Hampshire Republican gubernatorial candidate who has watched the candidates face repeated questions about the topic on the campaign trail. "This issue plays very well with Republican primary voters."

And it's clear they're listening.

Perry's sudden drop in the polls was largely attributed to weak debate performances involving his support for the Texas law. He suggested that Republicans who oppose the policy were heartless. And Romney fueled the tuition criticism every chance he got.

But Perry tried to neutralize the attacks this week. The outspoken Texan raised new questions at the debate about Romney's use of a landscaping company that employed illegal immigrants at his suburban Boston home several years ago.

For a moment, it looked as though Perry and Romney may come to blows as they debated the issue, with Romney at one point putting his hand on Perry's shoulder as the conversation began to heat up.

"The American people want the truth," Perry demanded. "They want to hear you say(...)More.