The Supreme Court will hear the case on same-sex marriage on Tuesday. As the hearing approaches, people continue to discuss the controversial topic.

Kate Shaw, an assistant professor of law at the Benjamin N. Cardozo School of Law in New York, talked to ABC News about the upcoming hearing.

Shaw clarified the major issue with same-sex marriage since some states allow it while others do not. "The Supreme Court has made clear ... that the Constitution prevents states from prohibiting interracial marriages," she said.

"So the question in this case is whether prohibiting same-sex couples from marrying is within the states' regulatory power, or whether it violates the U.S. Constitution."

Thirty-six sates including the District of Columbia allow same-sex marriage as a result of a June 2013 case that struck down part of the federal Defense of Marriage Act.

"Although the court in that case didn't explicitly rule that state bans on same-sex marriage were unconstitutional, lower courts in the wake of Windsor concluded almost uniformly that state marriage bans couldn't survive," Shaw said referring to United States v. Windsor.

Shaw clarifies Tuesday's hearing where, "The plaintiffs are committed same-sex couples who either wish to marry in their states and have been prevented from doing so or who have gotten married in other states and wish to have their marriages recognized in the states they live in."

Plaintiffs in the case are from four states that include Kentucky, Michigan, Ohio and Tennessee.

The Supreme Court will hear cases defending the right for same-sex couples to marry for two and a half hours, according to The Associated Press.

Obama's administration is backing the right to marriage for same-sex couples. Yet, the administration did not say what should be done if the Supreme Court denies equal rights for gay couples.

President Barack Obama personally announced his support for same-sex marriage back in 2012.