U.S. Sen. Lindsey Graham says America's retirement system could be at risk unless the nation's immigration problems get fixed.

In a speech to a Charleston business group, Graham said the U.S.'s graying population means there will be fewer workers in the job stream to keep stocking stressed government budget and benefit accounts, including Social Security.

And if the future economy includes millions of illegal workers who don't pay in, then benefits that a growing numbers of Americans will depend on for retirement will become even more drained, he said, pointing at an expected "tsunami" of retirements by 80 million Baby Boomers in the next decades.

"If you're down to two workers for every retiree, you better reform your immigration system," Graham said, "because you're going to need people from outside this country to fill the workforce."

Graham's comments came Thursday during the monthly Small Business Lunch at Halls Chophouse in Charleston.

Estimates are that there are between 11 million and 12 million illegal immigrants in the country today, many of whom are filling lower skilled positions in the manual labor, restaurant and home-building sectors - areas which often draw little scrutiny.

"It's not that Americans are lazy, we've just moved on," Graham said in describing the trend in what jobs are being taken.

Graham favors reforms that include securing the southern border, requiring immigrants to learn English, as well as backing a legal pathway to citizenship. He called it a more realistic approach than forcing millions out.

Immigration, meanwhile, could remain a hot-button issue in the November election where Graham faces three other challengers. They are Democrat Brad Hutto, Libertarian Victor Kocher and independent Thomas Ravenel.

Reached separately, Hutto's campaign said Thursday he favors a pathway to citizenship approach, as well, for those "willing to work, learn English, and pay taxes."

Kocher said his immigration ideas center on efforts to first secure the borders. He also supports going to a national sales tax in place of the income tax as a means of ensuring that everyone in the country pays their tax obligations at the point of sale.

Ravenel's campaign did not respond to phone and email messages.

Graham said Republicans have a good chance to re-gain control of the Senate this November by picking up as many as six seats. But he also said Republicans are suffering in the immigration debate as well by being too heavy-handed in their approach.

"Hispanics are pro-life, hard-working," he said. But unless the message changes, "we're going to drive them away."

Reach Schuyler Kropf at 937-5551