SACRAMENTO (CBS13) — The U.S. Supreme Court is set to rule on a historic same-sex marriage case, and the vote will likely come down to one justice with Sacramento ties.

Professor Larry Levine teaches a class on sexual orientation, gender identity and the law at McGeorge School of Law.

“It’s not certain, but expected that the Supreme Court’s going to say the Constitution does not allow you to prevent gays and lesbians from having access to this important institution of marriage,” he said.

He’s studied the gay marriage debate, specifically the role played by Justice Anthony Kennedy, who happens to be McGeorge’s longest-serving faculty member.

“It brings attention to us as a law school, to Sacramento,” he said.

Kennedy grew up in Sacramento and taught Constitutional law at McGeorge from 1965 until his appointment to the Supreme Court in 1988. Since then, he’s taught at McGeorge’s summer program in Austria.

With four justices leaning toward voting in favor of gay marriage and four others likely voting against it, Kennedy is widely believed to be the swing vote in the upcoming decision.

“He tends to go on the conservative side. but when it comes to issues of equality and more specifically LGBT rights, so far he has come down on the side of equality and LGBT rights,” Levine said.

Kennedy voted in favor of gay-rights activists and wrote the majority opinion in three prior cases.

“I think he’s really motivated by a sense of equality, and that different groups being treated differently just because one group is disliked is distasteful to him,” he said.

During April’s hearing, Kennedy questioned whether the court has the authority to redefine marriage.

If the court decides in favor of gay marriage advocates, the 14 states that do now allow gay marriage would have to start issuing marriage licenses to same-sex couples.