Washington ? The Senate majority leader said Sunday he supported a proposed constitutional amendment to ban homosexual marriage in the United States.

Sen. Bill Frist, R-Tenn., said the Supreme Court’s decision last week on gay sex threatens to make the American home a place where criminality is condoned.

The court on Thursday threw out a Texas law that prohibited acts of sodomy between homosexuals in a private home, saying that such a prohibition violates the defendants’ privacy rights under the Constitution. The ruling invalidated the Texas law and similar statutes in 12 other states, including Kansas.

“I have this fear that this zone of privacy that we all want protected in our own homes is gradually — or I’m concerned about the potential for it gradually being encroached upon, where criminal activity within the home would in some way be condoned,” Frist told ABC’s “This Week.”

“And I’m thinking of — whether it’s prostitution or illegal commercial drug activity in the home — … to have the courts come in, in this zone of privacy, and begin to define it gives me some concern.”

Asked whether he supported an amendment that would ban any marriage in the United States except a union of a man and a woman, Frist said: “I absolutely do, of course I do.

“I very much feel that marriage is a sacrament, and that sacrament should extend and can extend to that legal entity of a union between — what is traditionally in our Western values has been defined — as between a man and a woman. So I would support the amendment.”

Same-sex marriages are legal in Belgium and the Netherlands. Canada’s Liberal government announced two weeks ago that it would enact similar legislation soon.

Rep. Marilyn Musgrave, R-Colo., was the main sponsor of the proposal offered May 21 to amend the Constitution. It was referred to the House Judiciary subcommittee on the Constitution on Wednesday, the day before the high court ruled.

As drafted, the proposal says:

“Marriage in the United States shall consist only of the union of a man and a woman. Neither this Constitution nor the constitution of any state under state or federal law shall be construed to require that marital status or the legal incidents thereof be conferred upon unmarried couples or groups.”

To be added to the Constitution, the proposal must be approved by two-thirds of the House and the Senate and ratified by three-fourths of the states.

Frist said Sunday he respects the Supreme Court decision but feels the justices overstepped their bounds.

“Generally, I think matters such as sodomy should be addressed by the state legislatures,” Frist said. “That’s where those decisions — with the local norms, the local mores — are being able to have their input in reflected.

“And that’s where it should be decided, and not in the courts.”