The defeat of same-sex marriage in referenda across the country earlier this month left some gays gloomy, but those high-profile fights may have obscured changes in Congress that have, for the first time, put the gay community within reach of victory on its legislative agenda.

After languishing for 12 years, a bill to ban employment discrimination against homosexuals is likely to be passed by the House and Senate next year and sent on to President Bush, supporters and opponents of the legislation said yesterday.

“I think the prospects look great,” a gay rights advocate, Joseph Solmonese of the Human Rights Campaign, said. He added that incoming members of Congress should provide more votes for the measure, while the Democratic takeover of both chambers will limit the influence of Republicans who prevented floor action on the bill, known as the Employment Non-Discrimination Act, or Enda. “It’s significantly better when you look at who’s in charge,” Mr. Solmonese said.

“The chances of it passing are much higher than it’s ever been in the past,” a critic of the employment measure, Thomas McClusky of the Family Research Council, conceded. In 1996, the bill failed to pass the Senate, 49–50. It was never brought to a vote in the House.

The bill’s backers contend that it has long had the support of a majority in both houses. Whether the measure could win the 60 votes needed to overcome a filibuster is less clear, though many observers said it probably can.

“We would certainly try to bring the public pressure in trying to make sure there is a filibuster, but that’s not guaranteed,” Mr. McClusky said.

The wild card in any discussion about the gay rights bill is Mr. Bush. His stance on gay issues has been murky, and neither side is confident about whether he would sign or veto the measure.

“That’s the $64,000 question,” Mr. Solmonese said.

“We just don’t know where the president would come down on this, especially if it is on a piece of legislation considered must-pass,” Mr. McClusky said. “We’d hope he’d take a strong stand.”

Asked about the chances of blocking the legislation either on Capitol Hill or at the White House, he said, “I think it’s an uphill battle, period.”

During a debate in 2000, Mr. Bush gave a noncommittal answer when asked about his stance on the employment discrimination bill. “I support equal rights but not special rights for people,” he said.

Soon after he arrived in office, Mr. Bush faced pressure to repeal an executive order President Clinton issued in 1998 banning discrimination against gays and lesbians in the federal work force. Mr. Bush left the order in place, but his subordinates later came under fire for being reluctant to enforce the rule.

Mr. Solmonese said Mr. Bush’s previous statements on the employment bill are now of little value in figuring out what the president will do. “It’s all been a sort of meaningless political posturing. It’s always being said with the knowledge it’s never going to land on his desk,” the lobbyist said. “The equation has changed entirely now.”

Congressional action on the bill could also point up a curious and little-noted divide between two Republicans considering bids for the White House, Senator McCain of Arizona and Governor Romney of Massachusetts.

Mr. Romney, who is positioning himself as a conservative alternative to Mr. McCain, has expressed support for the federal anti-discrimination legislation. Mr. McCain, who is viewed as a moderate, opposes the measure.

In 1994, Mr. Romney embraced the newly drafted bill as he campaigned unsuccessfully to replace Senator Kennedy, a Democrat. In 1996, Mr. McCain voted against the gay-rights legislation.

Neither politician responded to requests yesterday for an explanation of their current position, though Mr. McCain seemed to stand his ground in an interview last week.

“I don’t believe we should discriminate against anyone in the workplace, but I don’t think we need specific laws that would apply necessarily to people who are gay,” the senator told ABC’s “This Week.”

Separate legislation providing penalties for crimes motivated by a victim’s sexual orientation also is expected to advance easily through Congress and may meet with little resistance from Mr. Bush.

Some Democrats also want to use their new power to press for an end to the military’s “don’t ask, don’t tell” policy toward gays in the ranks. Rep. Martin Meehan of Massachusetts introduced legislation last year to overturn the ban on openly gay troops and told the Boston Globe recently that he wants to hold hearings on the issue next year.

Gay activists acknowledged Mr. Meehan’s measure has little chance of passing now, but they hope the hearings will expose the current rules as unfair and harmful to national security.

Only 17 states ban discrimination against gays in the workplace. New York is among them. In the other 33 states, an employee can be fired or refused work based on his or her sexual orientation.

Opponents of such laws, and the federal bill, argue that sexual preference does not belong in civil rights laws that address discrimination based on race, gender, or handicap. “Behavior involves moral choices and skin color does not,” the director of the Virginia-based Culture and Media Institute, Robert Knight, said. “If sexual orientation is accorded the same clout in the law that is given to race, then people with traditional values will be treat as hate-filled bigots even if they have no hate in their hearts.”

Rep. Barney Frank, a Democrat of Massachusetts, said employers have no business policing employees’ personal lives. “Whom you date when you’re off duty should have no ability to cost you your job,” he told C-SPAN recently.

The most contentious part of the new bill may be a provision aimed at protecting transsexuals. Mr. Frank has settled on language to address the issue but is bracing for attacks from conservatives.

Mr. Knight said Democrats would be politically wise to shelve Mr. Frank’s bill, but they cannot. “That constituency is so strong within the Democratic Party that they would risk a schism if they put it on the back burner,” he said.