D.C. Council member David A. Catania said yesterday he has left the local Republican Party organization after its chairman stripped him of his delegate seat at the national convention because he opposes President Bush's reelection.

Catania, a lifelong member of the GOP and openly gay political activist, raised more than $50,000 for the Bush campaign in the past year but became a vocal critic after Bush called for a constitutional amendment banning gay marriage.

Carol Schwartz, the other Republican on the 13-member council, resigned as a delegate to the convention in protest of Catania's banishment.

Catania, in an interview, said he would have fulfilled his obligation and voted for Bush at the Republican National Convention in New York, "but I have no intention of supporting him in the general election."

"I have to look in the mirror and say, 'Are you at home behind your eyes supporting a person who would write discrimination into the Constitution?' There is simply no way I could rationalize that," Catania said.

The council member, who won his at-large seat in a special election in 1997, said he has not decided whether to change his party registration. "I would never change my principles, but I don't have to hang out in this crowd. There is such a thing called an independent," he said.

Betsy Werronen, chairman of the D.C. Republican Committee, acknowledged that she declined to certify Catania as a delegate to the nominating convention because he had said publicly that he would not support Bush for reelection. The D.C. delegates were chosen at a party caucus in February.

"David is our shining star," she said, "and we hoped that we could work out this thing. But at the end of the day, David does not support the reelection of the president, and so for me to be honest to myself, I can't certify that he does."

Catania, 36, said he raised $70,000 to $80,000 for Bush's reelection, earning him membership in the exclusive club of big-time fundraisers for the president. Catania was designated a "Maverick" -- people younger than 40 who raise at least $50,000. But he said he has asked the campaign to remove his name from the list.

Terry Holt, a spokesman for the Bush campaign, declined to comment on the dispute between Catania and the D.C. GOP and would not respond to Catania's criticism of the president. He said most voters will support Bush on such issues as "strong national security and a vibrant, prosperous economy," suggesting that "values issues" would not play a big role in voters' decisions. Asked about voters for whom the gay marriage issue is important, Holt said, "We would hope to win their support on the broad range of issues that unite all Republicans."

Patrick Guerriero, executive director of the Log Cabin Republicans, a group of gay GOP activists, called Catania's break with the party "a great loss . . . and what it is for us is another very harsh reminder of the fact that the effort to amend the United States Constitution is causing a culture war within the GOP."

He said other party activists are "agonizing over a thoughtful way to handle being delegates."

"Our organization will be in New York in record numbers and will do our best to let the Republican Party know we're not going to go away," Guerriero said.

Catania will be replaced in the 19-member D.C. delegation by Carl Schmid, another openly gay political activist, Werronen said. Schmid, who has worked on Catania's campaigns, said he was "in an awkward position" but will go to the convention and cast his ballot for Bush.

"David is my friend, and I opposed what [Werronen] is doing to David. I'm not happy with the president," he said. "But I do think it's important for a gay person to be there and to speak out."

Schmid also said Catania "perhaps did go too far at first" in hinting that he would work to defeat Bush in the fall.

Catania said yesterday he cannot support Bush any longer. "In 2000, I supported a person who said, 'I am a compassionate conservative and a uniter, not a divider,' " he said. "Now he's decided, 'I'm not a uniter.' He picked an issue that is driving a wedge within the American family and is using it for crass political purposes. You don't hear much anymore about compassion in the White House."

David A. Catania has been a D.C. Council member since 1997.