The Supreme Court heard oral arguments Tuesday on three cases that will decide whether employers can discriminate based on sexual orientation and transgender status.

The plaintiffs argue that the Civil Rights Act of 1964, which bars sex discrimination, should be read to forbid discrimination against gay and transgender employees. According to reports from the courtroom, the court appeared divided between the liberal and conservative justices on the issue. Justice Neil Gorsuch seemed at times sympathetic to the plaintiffs’ arguments, but also expressed concern about “massive social upheaval” should the plaintiffs prevail in the case.

Outside the courthouse, LGBTQ activists demonstrated in support of the plaintiffs. “Orange Is the New Black” star Laverne Cox attended the arguments and spoke at a press conference on the courthouse steps.

“I hope that no matter what our justices decide, that Americans know that it should not be OK to discriminate against someone simply for being who they are,” Cox said. “If we do not win this case … then our Legislature needs to make it clear that discrimination against anyone because of who they are should not be the way we live our lives here in the United States of America.”

Two of the cases involve a skydiving instructor and a Georgia county government employee who allege they were fired because they are gay. The third case involves Aimee Stephens, a Michigan funeral home director who says she was fired after she transitioned to living as a woman.

Federal law does not explicitly protect gay and transgender people from employment discrimination, and such protections are afforded in fewer than half the states. The plaintiffs argue that LGBTQ discrimination is a form of sex discrimination, and is therefore forbidden under federal law.

The American Civil Liberties Union argued the case on behalf of Stephens.

“When Aimee Stephens was fired because of who she is, not because of her performance at work, she was denied what Congress sought to give,” argued David Cole, the ACLU’s national legal director, outside court. “All we are asking the court to do is to recognize that transgender people have the same rights under our civil rights laws as everybody else not to be discriminated against because of their sex.”

John Bursch, of the Alliance Defending Freedom, argued the case for R.G. & G.R. Harris Funeral Homes, which fired Stephens when she announced that she would begin transitioning.

“Our federal law prohibiting discrimination because of sex. Title VII is a promise that women will not be treated worse than men and men will not be treated worse than women,” Bursch said outside court. “The law’s text does not mean that employers must treat biological men as women.”

A ruling is expected sometime next year.