LOS ANGELES (CNN) -- Republican presidential candidate Tommy Thompson apologized Friday morning for saying in last evening's debate that private employers should be allowed to fire gay employees because of their sexual preference.

Thompson was asked by the moderator: "If a private employer finds homosexuality immoral, should he be allowed to fire a gay worker?"

The former Wisconsin governor answered: "I think that is left up to the individual business. I really sincerely believe that that is an issue that business people have got to make their own determination as to whether or not they should be." The moderator appeared a bit startled: "OK, so the answer is yes?" Thompson replied, "Yes."

In a telephone interview from O'Hare Airport, Thompson told "American Morning" that he "misinterpreted" the question and should have asked to have it repeated.

"That's never been my position," Thompson said, said adding that discrimination isn't acceptable.