MOUNT PLEASANT — Republican 1st District Congressional hopefuls Mark Sanford and Curtis Bostic said Saturday that the issue of gay marriage and civil unions should be settled at the state level, not by U.S. Supreme Court rulings.

Their comments came as they made their final joint appearance in Charleston, a half-hour debate carried live on WCDB-TV’s “Beyond the Headlines” program and moderated by Brad Franko.

The gay marriage issue made national news last week as the Supreme Court heard two related cases, but it hasn’t been a big talking point in the GOP primary. Sanford and Bostic said they support a traditional definition of marriage as between one man and one woman.

Bostic said he would support a constitutional amendment to that effect, while Sanford said he viewed marriage more as a religious sacrament than the business of the state.

“I think we have to have a debate as Americans as, ‘OK, let’s sort things out,” Sanford said. Bostic added, “This is an issue reserved to the states. This is a debate among the people.”

GOP voters will go to the polls Tuesday to decide whether they want Sanford, a former governor and congressman, or Bostic, a former Charleston County councilman, to be their nominee for the race to fill the House seat vacated by U.S. Sen. Tim Scott.

During Saturday’s show, both also voiced their opposition to Charleston County’s half-cent sales tax, which county voters approved in 2004 while Sanford and Bostic were in office. And both expressed wariness about military involvement on the Korean peninsula.

“We need to be very deliberate before we extend the use of force,” Bostic said. Sanford said the nation’s economic health is vital to maintaining its military supremacy.

The lightest moment came during a break, when Franko said ideally he would have done the debate in blue jeans at a local coffee shop, rather than in a suit and tie inside a chilly TV studio.

“I think both of us are more bent toward that kind of discussion,” Bostic said, and Sanford agreed — “we can leave right now.”

The two aren’t expected to appear together again in the Charleston area before Tuesday’s vote, but they are expected to meet in Beaufort on Monday.

Tuesday’s winner will face Democrat Elizabeth Colbert Busch and Green Party candidate Eugene Platt on May 7.

Reach Robert Behre at 937-5771.