WASHINGTON — The Supreme Court is hearing the case Monday of a Christian graphic artist who objects to designing wedding websites for gay couples, a dispute that’s the latest clash of religion and gay rights to land at the highest court.

The designer and her supporters say that ruling against her would force artists — from painters and photographers to writers and musicians — to do work that is against their faith. Her opponents, meanwhile, say that if she wins, a range of businesses will be able to discriminate, refusing to serve Black customers, Jewish or Muslim people, interracial or interfaith couples or immigrants, among others.

The case comes at a time when the court is dominated 6-3 by conservatives and following a series of cases in which the justices have sided with religious plaintiffs. It also comes as, across the street from the court, lawmakers in Congress are finalizing a landmark bill protecting same-sex marriage.

The bill, which also protects interracial marriage, steadily gained momentum following the high court’s decision earlier this year to end constitutional protections for abortion. That decision to overturn the 1973 Roe v. Wade case prompted questions about whether the court — now that it is more conservative — might also overturn its 2015 decision declaring a nationwide right to same-sex marriage. Justice Clarence Thomas explicitly said that decision should also be reconsidered.

The case being argued before the high court Monday involves Lorie Smith, a graphic artist and website designer in Colorado who wants to begin offering wedding websites. Smith says her Christian faith prevents her from creating websites celebrating same-sex marriages. But that could get her in trouble with state law. Colorado, like most other states, has what’s called a public accommodation law that says if Smith offers wedding websites to the public, she must provide them to all customers. Businesses that violate the law can be fined, among other things.

Five years ago, the Supreme Court heard a different challenge involving Colorado’s law and a baker, Jack Phillips, who objected to designing a wedding cake for a gay couple. That case ended with a limited decision, however, and set up a return of the issue to the high court. Phillips’ lawyer, Kristen Waggoner of the Alliance Defending Freedom, is now representing Smith.

Like Phillips, Smith says her objection is not to working with gay people. She says she’d work with a gay client who needed help with graphics for an animal rescue shelter, for example, or to promote an organization serving children with disabilities. But she objects to creating messages supporting same-sex marriage, she says, just as she won’t take jobs that would require her to create content promoting atheism or gambling or supporting abortion.

Smith says Colorado’s law violates her free speech rights. Her opponents, including the Biden administration and groups such as the American Civil Liberties Union, the NAACP Legal Defense & Educational Fund, disagree.

Twenty mostly liberal states, including California and New York, are supporting Colorado while another 20 mostly Republican states, including Arizona, Indiana, Ohio and Tennessee, are supporting Smith.

The case is 303 Creative LLC v. Elenis, 21-476.