On Tuesday, the Supreme Court hears arguments on same-sex marriage, which is now legal in about three dozen states.
But it's also legal in most states to discriminate against lesbian, gay, bisexual and transgender (LGBT) people in the areas of employment, housing and public accommodation.
So in many states, a person could marry someone of the same gender and then get fired for being gay.
"Most states have no non-discrimination protections for LGBT people," says David Stacy, government affairs director for the Human Rights Campaign, a national gay-rights group. "With limited or no federal protections, an LGBT person can get legally married in most states, but then be evicted from an apartment and denied a home loan."
Gay rights activists are urging state lawmakers to change anti-discrimination laws — which already include things such as race, age, religion and disability — to include LGBT people.
Religious groups opposed to gay marriage argue that the public accommodation element would unfairly require business owners to serve same-sex couples, even if they have a moral or religious objection.
"The public accommodation part is the part where you would think about the florist or the baker, who [is] saying, 'Hey, I can't do this in good conscience,' " Randall Wenger, chief counsel for the Pennsylvania Family Institute, told NPR's Jeff Brady recently. "And the question is, do you as a society force them to do that out of principle?"