Matt McTighe, director of the new group Freedom for All Americans, speaks in Portland, Maine, in November 2012 about legalizing same-sex marriage. (Joel Page/Associated Press)

Gay rights groups anticipating a Supreme Court victory on same-sex marriage later this month already are turning their attention to their next big priority: broad new legal protections against discrimination in the workplace and other parts of society.

The new campaign is aimed at enacting protections at the federal level and in 28 states where civil rights statutes do not explicitly ban discrimination against gay and transgender people.

Propelled by $25 million from wealthy backers, the effort promises to open a volatile new front in the nation’s culture wars, both on Capitol Hill and in statehouses nationwide.

Social conservatives are bracing for battle. They argue that anti-discrimination laws infringe upon the religious liberties and free-speech rights of employers and others who oppose homosexuality or same-sex marriage on moral grounds.

Gay rights advocates counter that a court ruling establishing a national right to same-sex marriage would highlight a fundamental injustice: That in many states, the newly legal marriages could get the brides and grooms fired.

“The ability to live openly and to earn a living is so central to every American and certainly every LGBT American,” said Matt McTighe, director of Freedom For All Americans, a new campaign involving many of the same activists and funders who drove the marriage battle. “It’s high time we addressed this from a legislative standpoint.”

Nineteen states and the District bar employment discrimination on the basis of gender identity and sexual orientation, according to the Movement Advancement Project, a gay rights think tank. Three more states have protections that extend only to gay people.

But the remaining states and the federal government have no explicit legal protections for either group in their civil rights statutes. Although court rulings are increasingly relying on other ways to protect these groups, gay rights advocates say the lack of explicit protections has left the door open for discrimination, not only in the workplace but also in housing, public accommodations and other arenas.

Jimmie Beall, a lesbian from Ohio, lost her contract to serve as a public high school government teacher in 2003 after a controversy arose around her sexual orientation. In an interview, Beall said she contacted the state’s civil rights commission shortly after being terminated and was stunned to learn that Ohio had no explicit laws barring employers from firing workers for being gay.

She sued anyway. Three years later, the school district agreed to settle the case. Despite the favorable outcome and the fact that she landed a job in a more accepting environment, Beall said she went through an emotional wringer that could have been avoided if clear anti-discrimination laws had been on the books.

At one point, for example, Beall said she considered legally relinquishing her two biological children from a previous marriage to her partner. Attorneys told her that was the only way the children, who would have been left without health insurance when Beall’s contract expired, could be covered under her partner’s policy.

“You can’t breathe. You can’t sleep. You can’t eat when all of that ground has fallen below you and you have no idea how it’s going to work out and how you’re going to survive it with your family intact,” said Beall, 55.

In recent years, lawsuits such as Beall’s have been increasingly successful. Despite the lack of explicit laws protecting gay and transgender workers, courts have granted relief under federal employment laws that ban discrimination on the basis of gender, said James Esseks, director of the lesbian, gay, bisexual, transgender and HIV project at the American Civil Liberties Union.

This is particularly true for transgender workers. A 2012 ruling by the Equal Employment Opportunity Commission extended the definition of sex discrimination to encompass discrimination on the basis of gender identity.

Social conservatives say this proves that expanded protections for gay and transgender people are unnecessary. Plus, employers are increasingly adopting internal policies to protect gays against discrimination.

“Governments do not need to coerce businesses by creating special privileges based on sexual orientation and gender identity,” said Ryan T. Anderson, a senior research fellow at the conservative Heritage Foundation. “The market will — and already is — sorting this out.”

Meanwhile, they point out, anti-discrimination laws have hurt the livelihoods of some Christian business owners — primarily bakers, photographers and florists who have been sanctioned or gone out of business after refusing to provide services for same-sex ceremonies.

In several states, conservative groups have pushed to bolster legal protections for these religious objectors, with mixed results. In Indiana, a statewide religious liberties bill sparked a national controversy earlier this year, prompting the state’s Republican leaders to soften its language.

Conservatives say a Supreme Court decision in favor of same-sex marriage would galvanize activists to fight harder for religious-freedom laws and against anti-discrimination measures.

The Alliance Defending Freedom, a Christian-based public interest law firm, is urging churches and faith-based nonprofit groups and schools to take defensive action. The firm has distributed thousands of copies of a 44-page booklet titled, “Protecting Your Ministry From Sexual Orientation and Gender Identity Lawsuits,” with sample mission statements and recommendations for rewriting bylaws to fortify against discrimination claims.

“We’re identifying those places where we understand that people are going to need protection on religious-freedom and freedom-of-conscience grounds and engaging allies in those states,” said Greg Scott, an Alliance spokesman.

Gay rights advocates vow to press ahead. The Freedom for All Americans campaign, which is based in Washington, has efforts underway in eight states to pass anti-discrimination laws or oppose religious-liberties bills. Ultimately, activists hope to persuade Congress to address the issue; comprehensive legislation could be introduced as soon as this year.

McTighe, the campaign’s director, said he hopes to channel the energy of the same-sex marriage fight into this more fundamental battle, which would benefit a broader cross-section of the gay, lesbian, bisexual and transgender community. Among those financing the campaign are software entrepreneur Tim Gill and hedge fund managers Daniel Loeb and Paul Singer — all of whom supported the marriage fight.

“What we’re trying to do with this new entity is to harness that momentum,” McTighe said, “and make sure we don’t lose sight of the fact that there is more work to be done.”