But gay men and women can still be fired and denied housing in vast stretches of the country, especially in the South and the Mountain West. There are 16 states where gay people lack virtually any legal protections. Officials at the federal Equal Employment Opportunity Commission, who investigate claims of workplace discrimination, said they had received more than 1,300 complaints involving sexual orientation and gender identity since 2013, when they began tracking such claims.

In Yankton, S.D., for example, Tyler Brandt, 16, said his manager at a Taco John’s restaurant required him to wear a name tag that said “Gaytard.” Humiliated, he quit, and he is now represented by the American Civil Liberties Union, which filed a claim with the commission. A Taco John’s spokeswoman said the company took the allegations “very seriously” and is in the process of resolving the claim.

In Connecticut, Kerry Considine, a physical therapist at an assisted living facility, tried to add her wife, Renee, to her health insurance policy and was denied; the company was based in Tennessee, which does not recognize same-sex marriages. The company eventually agreed to cover Renee Considine, but not until her wife filed a claim with the commission. Kerry Considine is now suing in federal court, in part to recover expenses incurred when her wife was not covered and also to establish that the denial of benefits was discriminatory.

“If I was a man marrying a woman, there wouldn’t have been a question,” she said.

Against that backdrop, lawyers for an array of gay rights and civil rights groups — including the A.C.L.U., the Lambda Legal Defense Fund and the Human Rights Campaign — have been meeting for the past six months to work on a proposed bill. The Human Rights Campaign has been convening focus groups to gauge public opinion on the plan. On Thursday, it issued a report making the case that a broad civil rights bill would “make ours a more equal nation,” as Chad Griffin, the president of the group, wrote. The Center for American Progress, a liberal research organization, will issue its own report next week.

The push signals a major change in strategy. For the past 20 years, gay rights advocates have tried, unsuccessfully, to pass much narrower legislation banning discrimination only in employment. Now, with analysts predicting that the Supreme Court will soon legalize same-sex marriage in all 50 states, movement leaders have coalesced around the broader approach.