"The person who hired them is going to have to deal with it," Norman said in an interview Thursday mor- ning. Later, he said, "You found people who aren't even working for me."

Norman, a Republican, said stopping the flow of illegal immigrants is the "number one issue for me." His two TV ads, which started last month, focus on the issue. A third, scheduled to start today, criticizes his opponent, U.S. Rep. John Spratt, a York Democrat, on immigration issues.

"Illegal aliens have flooded our borders for years, while politicians just watched," a video of one ad says on Norman's Web site.

Immigration has become an explosive issue nationwide as the number of illegal immigrants has soared to an estimated 12 million from 3.5 million in 1990. South Carolina is home to 55,000 illegal immigrants. North Carolina has 390,000.

Hiring illegal immigrants is against the law. But federal law doesn't require employers to verify workers' immigration status or whether their documents are valid. That 20-year-old loophole has enabled illegal immigrants to get jobs, which has helped fuel the surge in illegal entry.

"We do what the law requires," Norman said.

There are free, federal programs available to employers to verify Social Security numbers and immigration status. The programs are voluntary, but such worker verification has been part of immigration-reform bills in both the House and Senate.

Immigration-control advocates are especially supportive of the tools.

"Employment is a paramount goal for a large share of illegal immigrants," said Steve Camarota, research director with the Center for Immigration Studies, a Washington think-tank advocating controlled immigration. "So we have to make an effort to cut them off as much as possible from jobs."

Norman said Thursday that he didn't know about the existing verification programs. Initially, he said he would "absolutely not" require contractors on his projects to use the programs. Later in the day, he said he'd check into the programs and would consider requiring contractors to use them.

However, he said: "It's unfair to say business should take responsibility for the government. That's why I'm in this race, to control the borders."

Spratt said Thursday that companies should be required to use verification programs, but that they need to be more reliable.

Norman said his companies follow the federal law, which requires visually inspecting worker's identification. He said that over the years he has received several notices that workers' Social Security numbers did not match official records.

Illegal immigrants using fake or stolen numbers to get jobs are a major cause of millions of such mismatches. Norman said that when notified, his companies ask workers to correct the problem. If they can't, he said they are let go. The Observer identified and visited properties owned by Norman, his family and several of his businesses and spoke with workers. Two construction workers at Shiland Village, a Rock Hill office and retail project on Celanese Road, said they were illegal immigrants from Mexico. Norman and his brother David own the property.

Across the road, one construction worker at Warrington Place, a townhouse development, said he came here illegally from Mexico.

Signs identified both sites as Warren Norman Co. developments.