Ivan Segura, a U.S. citizen who was born in Mexico, shakes his head when the Republican presidential candidates talk about illegal immigration.
"They're not talking about what to do about those who are already here," said Segura, who works as an advocate for immigrants in South Carolina. "How are you going to get 12 million people out of the country? Where are you going to get the money? How are you going to identify them? Give me some workable solutions."
Halting the flow of illegal immigrants into the country - and figuring out what to do about those already here - has become a major issue in the GOP presidential primary, triggering sparks between the dueling candidates.
Some, including Segura, say none of the Republican candidates is offering a workable, realistic solution, such as a path to citizenship for illegal immigrants already in the country.
Perhaps more than any other issue, illegal immigration is a tricky topic for the GOP contenders. Each time they speak, candidates risk offending someone - Republicans who want a crackdown or the growing number of Hispanic voters who are U.S. citizens.
"It is an explosive issue," said Dave Woodard, a Clemson political scientist and pollster. "It's an emotional issue. There's no way for candidates to answer the questions that doesn't offend someone. You have peach farmers saying, 'We need these workers.' And you have other voters saying, 'It's not fair for them to be in the country.'"
"The candidates have all gravitated to talking about securing the border, building that fence (along the U.S.-Mexico border)," Woodard said. "But there hasn't been much talk on the tougher part on what to do with those already here."
The local impact
Citing what they see as lack of action on the federal level to stem illegal immigration, state lawmakers around the country, including in South Carolina, are pushing through tough, controversial reforms themselves.
South Carolina's new immigration law, requiring law enforcement to check the immigration status of motorists they stop, has been challenged in a federal lawsuit this month by immigrant-advocacy groups. They say the law, set to go into effect Jan. 1, will encourage racial profiling and violate the constitutional rights of those stopped.
Long-term, state lawmakers say the federal government must step up and solve the issue.
The Republican presidential candidates each advocate many of the same solutions to address the problem, including enforcing the laws already on the books, securing the border by building walls, utilizing unspecified technology and deploying the National Guard to the border.
Perry's Achilles heel?
Only one candidate has first-hand experience with tackling the problem - Texas Gov. Rick Perry, who catapulted to the top of the polls after announcing his candidacy in Charleston in August only to fade into the background.
In the most recent poll, released last week, Perry was favored by just 9 percent of likely S.C. GOP primary voters. Perry's drop in the polls is the result of his poor performance in GOP debates, where he failed to fend off critics on the issue of illegal immigration, in particular.
A key debating point has been an education bill that Perry signed into law in 2001, allowing some illegal immigrants in Texas to pay in-state tuition rates if they had lived in the state for three years, had a Texas high school diploma or the equivalent and had applied for citizenship.
Perry has defended the law several times, saying opponents "don't ... have a heart."
Nationally, Perry supports building a fence along some areas of the border, opposes amnesty for immigrants illegally in the country, and wants the federal government to provide more border patrol agents and National Guard units to secure the border.
"The strange thing is, he's had some real successes on immigration," said Larry Sabato, a University of Virginia political scientist, referring to Perry's use of Texas taxpayers' money to help secure the border. "His campaign was late getting that information out there."
The campaign of former Massachusetts Gov. Mitt Romney, a GOP frontrunner, also is making political hay out of parts of Perry's immigration record.
It points to Homeland Security data that show that, between 2000 and 2010, Texas' illegal immigrants increased by an estimated 60 percent to nearly 1.8 million while the population in California and Florida, the other two states with the largest illegal-immigrant populations, stayed relatively flat.
Various groups have come to Perry's defense, saying border patrol is a federal issue and no one statewide elected official can have significant impact on a state's population.
Also, Perry - who raised $17 million in the most recent quarter, more than any of his opponents - has the money to go on TV and better explain his immigration stance, Sabato said. "You can't count anyone out with that kind of money."
Presidential candidate Herman Cain has been roughed up over immigration, too.
This month, the Georgia businessman proposed, then backed away from, building a 20-foot-tall, electrified border fence with barbed wire on top to halt the flow of illegal immigrants across the U.S.-Mexico border. Cain also suggested the fence have a warning sign - in English and Spanish - stating it is deadly.
In media accounts, Cain said he was joking.
Hispanic advocacy groups condemned the remark. "Cain may have been 'joking,' but suggesting that murder is a way to address illegal immigration just isn't funny," said Frank Sharry, director of the national immigration advocacy group, in a statement.
But the biggest damage to Cain could be with likely Republican voters who could see his backtracking as an indication that he is flip-flopper - a criticism usually reserved for his rival, Romney.
"He asking for a lot of do-overs," Sabato said. "He's got one on al-Qaeda and whether to release Americans, the 9-9-9 (tax) plan that he can't explain parts of and the electric fence."
(In a debate this month, Cain said he would be willing to exchange hundreds of prisoners at Guantanamo Bay for one U.S. soldier. Later questioned by the media about his apparent willingness to negotiate with terrorists, Cain said he misspoke.)
"The more scrutiny he gets, the more likely he is to fall apart," Sabato said. "It points to Cain's political inexperience."
Still Cain remains a leader in polls, including the most recent one in South Carolina, where he favored by a third of likely GOP primary voters.
While Perry has sank and Cain has rose, Romney has finished first or second in nearly all GOP polls, leading some politicos to speculate he has the best chance of becoming the Republican nominee.
But at last week's Las Vegas debate, Perry pounded Romney on immigration. Reviving a charge from the 2008 GOP presidential primary contest, Perry accused the former Massachusetts governor of using a lawn-care contractor that employed illegal workers to tend his yard.
"You stood here in front of the American people and did not tell the truth that you had illegals working on your property," Perry said to Romney during the debate. "The newspaper came to you, brought it to your attention. And you still, a year later, had those individuals working for you."
In 2006, The Boston Glove reported on the lawn-care company's use of illegal immigrants and Romney promised to look into it. A year later, the newspaper found the company continued to employ illegal workers who worked on Romney's yard.
Romney has said he put the company on notice that it could no longer employ illegal workers after the newspaper alerted him to the situation. When he discovered the firm still was employing illegal workers, Romney said he fired it.
"I'm running for office, for Pete's sake; I can't have illegals," Romney said in last week's debate.
Still, the attack put Romney on the offensive and, for the first time in the debates, ruffled his feathers.
Romney's camp has dismissed the attack as proof of Perry's desperation, but some politicos say it was a tactical win for Perry.