WASHINGTON, April 29 — Republican leaders in Congress gave strong backing to Senator Rick Santorum today, dismissing calls by gay rights groups and Democrats for him to be replaced as the third-ranking Republican in the Senate for remarks about homosexuality.

Senior officials in both houses swiftly rose to Mr. Santorum's defense as Congress returned from a two-week recess and the lawmakers faced questions about him from reporters.

"I think Senator Santorum took a very courageous and moral position based upon principles and his world view," said Representative Tom DeLay, the House majority leader from Texas.

Mr. Santorum, a Pennsylvania Republican who is the chairman of the Senate Republican Conference has been caught in a storm since he discussed a Texas antisodomy law under review by the Supreme Court during an interview with The Associated Press.

Referring to sodomy, he said, "If the Supreme Court says that you have the right to consensual sex within your home, then you have the right to bigamy, you have the right to incest, you have the right to adultery. You have the right to anything."

The remarks sparked outrage from gay rights groups, Democrats and a few moderate Republicans who suggested he should apologize or be replaced in the upper echelon of the Senate hierarchy. They made comparisons to the way Senator Trent Lott of Mississippi, the former Republican leader, was pushed aside after comments seen as racially divisive.
But Senator Bill Frist of Tennessee, the majority leader, said today that Mr. Santorum's support among his fellow Republicans in the Senate was solid.
"Absolutely, he will remain in leadership," Dr. Frist told reporters. "He has the full, 100 percent confidence of the Republican leadership in the United States Senate."

Dr. Frist went on to praise his colleague for his "inclusiveness, in terms of growing the Republican Party."
Officials said Mr. Santorum thanked his fellow Republican senators for their support in a closed strategy luncheon and received a round of applause.

People at the meeting said Mr. Santorum even received expressions of support from fellow Republicans who last week had expressed some misgivings about the comments.
Mr. Santorum, who did not speak in public today, has refused to apologize and said that his remarks were more directed at the right to privacy rather than homosexuality. He said his position was shared by a majority of the Supreme Court in upholding a Georgia antisodomy law in 1986.
Mr. DeLay repeated that point today, saying the court found "that it is very dangerous to say that whatever you do behind closed doors is your right to privacy."