SAN FRANCISCO — Gay Republicans are in a state of mourning over Mayor Giuliani’s exit from the presidential race, but they are moving swiftly into Senator McCain’s fold despite concerns that he has not always been faithful to their agenda.

“Giuliani was my man,” a political organizer in San Francisco’s gay community, Christopher Bowman, said. “I’m heartbroken he will not be the nominee of the party.”

A organization that is effectively the party’s gay caucus, the Log Cabin Republicans, posted a message at the top of the group’s main Web page Wednesday saluting Mr. Giuliani for his bid and his “service to our country.”

In the Bay Area, most gay Republicans were in the Giuliani camp, but some took a wait-and-see attitude in recent days, Mr. Bowman said. “When his numbers tanked, a lot of people who were voting absentee decided to hold on to their ballot and see if he’d still be in the race come February. Most of the people had McCain as a second choice,” the organizer said.

“Now, a lot of people are getting behind McCain, especially with the endorsement and Giuliani going behind McCain as well,” a former president of the New York chapter of the Log Cabin Republicans, Scott Musch, said.

While Mr. Giuliani’s record on gay issues was considered first-rate by many in the community, the Arizona senator’s stance is somewhat more complicated. He won praise from many for having led the fight in 2004 against a federal constitutional amendment to ban gay marriage.

“He went on the Senate floor and gave an impassioned speech saying it went against the very core of our constitutional ideals,” Mr. Musch said.

“John McCain was there on the barricades,” Mr. Bowman said.

However, in 2000, while he was running for the Republican presidential nomination against President Bush, Mr. McCain endorsed a California ballot measure that blocked the recognition of same-sex marriages. The proposition passed with 61% of the vote.

“That pissed off some people who had previously supported him,” Mr. Bowman said.

In 2006, Mr. McCain again upset gays and lesbians by making television ads in support of an Arizona constitutional amendment that banned same-sex marriage and prevented local government from offering benefits to unmarried domestic partners. The measure failed in Arizona, but similar ones passed in seven other states that year.

Part of the move toward Mr. McCain can be explained by the distaste in the gay community for the two other top-tier Republican hopefuls, a former Massachusetts governor, Mitt Romney, and a former Arkansas governor, Michael Huckabee.

“Romney isn’t going to get Log Cabin support at all, considering his about-face on most of the things he stood for in the Massachusetts government when he was an ally of ours,” Mr. Musch said. Mr. Romney once said he would be better for gay rights than Senator Kennedy, but in more recent years crusaded against a court ruling that legalized gay marriage in the Bay State. “He’s turned 180 degrees around,” Mr. Musch complained. Mr. Huckabee, a former Baptist preacher, is at odds with the gay community on many issues. He not only opposes gay marriage but also has suggested that homosexuality is akin to bigamy and bestiality.

“I think the radical view is to say that we’re going to change the definition of marriage so that it can mean two men, two women, a man and three women, a man and a child, a man and animal,” he told a religion Web site, Beliefnet.com. “Once we change the definition, the door is open to change it again.”

Some of the reasons why Mr. Huckabee is a nonstarter with the gay community were evident as he campaigned yesterday in a gay bastion, San Francisco. He told a forum that he would defer to the military’s “don’t ask, don’t tell” policy toward homosexuals — an approach that many gays view as discrimination. “The military should make that decision,” Mr. Huckabee said. “The purpose of the military is not to create social experiments. It is to make sure we protect our nation.”

At a news conference, Mr. Huckabee said he opposed discrimination against gays in the workplace. “I don’t think people should be hired or fired on that basis. There are people who have worked in the governor’s office for me who were gay, and it was never an issue,” he said.

However, when asked whether he would support a federal law to ban discrimination against homosexuals, the former Arkansas governor equivocated. “I’d have to study that to find out, are there instances where people are being fired for that express reason? If there is, then that would have to be, certainly, examined,” he said. While Republicans are a minority in the gay community, there has long been fiscally conservative, socially libertarian strain in gay thought. The method for allocating Republican delegates in California also tends to magnify the power of party members in places with a light Republican presence overall, like the Bay Area.

Mr. Bowman said one thing that could drive some Log Cabin members away from Mr. McCain would be a candidacy by Mayor Bloomberg, who has openly embraced gay rights. “If Bloomberg gets in the race, that would be a difficult time for a number of people. I hope Bloomberg stays out,” the organizer said.