Rick Perry, Mitt Romney, Michelle Bachman and GOP Candidates Spar on Immigration, Border Fence

Sept 12: Republican presidential candidates, from left, Rep. Michele Bachmann, R-Minn, former Massachusetts Gov. Mitt Romney and Texas Gov. Rick Perry before a Republican presidential debate in Tampa, Fla.

Sept 12: Republican presidential candidates, from left, Rep. Michele Bachmann, R-Minn, former Massachusetts Gov. Mitt Romney and Texas Gov. Rick Perry before a Republican presidential debate in Tampa, Fla.  (AP)

The honeymoon is over. Rick Perry was on the defensive during Monday night's GOP debate and his opponents for the Republican nomination were the reason why.

The Texas governor says a massive fence along the U.S.-Mexican border isn't the answer to the nation's immigration challenges and instead says Washington should send thousands of border agents and National Guard to patrol the area.

Perry faced tough immigration questions during Monday's Republican presidential debate. Perry says Texas offered incentives for undocumented immigrants to contribute to their communities, including in-state tuition rates for those who wanted to pursue higher education.

Perry said it was not feasible to build a fence the entire length of the Texas-Mexico border. And he defended his decision to grant in-state college tuition to illegal immigrants seeking U.S. citizenship.

His approach to immigration is similar to that of his predecessor, President George W. Bush. But like Bush, he found an unreceptive audience among conservative voters.

"Of course we build a fence, and of course we do not give in-state tuition credits to people who come here illegally," Romney said. "That only attracts people to come here and take advantage of America's great beneficence."

Former Utah Gov. Jon Huntsman agreed.

Perry asked for understanding. Mexico "has a clear and a long relationship with this state," he said of Texas. Illegal immigrants who go to college can become productive residents instead of staying "on the government dole" for the rest of their lives, he said.

"It's working well in the state of Texas," Perry said.

Over the next few weeks and months, his rivals seem determined to show that what works well in Texas might not work for the nation as a whole.

His rivals also seized on his record as a whole, saying Perry was rewarding illegal behavior. Rep. Michele Bachmann of Minnesota says taxpayer dollars shouldn't pay for benefits for those who have broken U.S. laws. Former Utah Gov. Jon Huntsman says Perry's position on the border fence is "treasonous." Former Massachusetts Gov. Mitt Romney adds that immigrants don't want government hand-outs.

Perry, holding his own but looking besieged at times, defended himself vigorously on most fronts. He acknowledged mishandling a schoolgirl vaccination program, however, and asked for understanding about Texas' need to work with illegal immigrants who seek citizenship and college educations.

As President Barack Obama might say: Welcome to the role of an incumbent with a complex record to defend from critics on all sides.

The spirited exchanges showed that the top Republican candidates differ not merely in style but on key issues such as immigration, health policy and Social Security. For now, at least, Perry is the front-runner the others are hoping to catch.

Romney, the former one-term Massachusetts governor running second in recent GOP polls, tried to blunt Perry's strongest point — his Texas jobs record — while exploiting what might be Perry's most troublesome issue, Social Security.

The deeply conservative Tampa audience seemed to shift to and from Perry's side during the two-hour forum, sponsored by CNN and the Tea Party Express.

On Social Security, Romney said, it wasn't so bad that Perry has called the program "a Ponzi scheme." The bigger problem, he said, is Perry's writings that suggest Social Security is unconstitutional.

"Does Gov. Perry continue to believe that Social Security should not be a federal program, that it's unconstitutional and it should be returned to the states?" Romney said.

The federal government made mistakes when Social Security was created decades ago, Perry said. However, he said, "obviously we're not going to take that program away" now that retirees have counted on it for 70 years.

The Associated Press contributed to this story.

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