Paul Katami and his partner Jeff Zarrillo, two of the plaintiffs in the case, are from Southern California, and they'll soon be on their way to our nation's capitol. It's an issue they hope will be decided once and for all at the federal level.
"It really has never made any sense to us because we have jobs where we could relocate that we could have rights in one state, and cross a state line and those rights would dissipate. This is the United States of America not the Divided States of America," said Zarrillo.
Zarrillo and Katami are one of two couples challenging the constitutionality of Prop 8. Their attorneys will argue it violates equal protection clauses of the 14th Amendment.
In November 2008, a majority of California voters approved the measure to keep marriage between a man and a woman. Randy Thomasson is a Prop 8 supporter and the president of Save California.
"We should not allow the federal judiciary to destroy the vote of the people," he said.
Thomasson says Prop 8 is not a civil rights issue.
"Marriage is for a man and a woman. That's not only historical, it's natural. You need to have a man and a woman to have a baby, to conceive. Children do best with a married father and mother under the same roof," he said.
Katami and Zarrillo disagree, and look forward to starting a family as a married couple.
"This is an American issue that focuses on equality. If you are an American, you deserve the equal rights that are afforded to us on the day we were born from our Constitution," said Zarrillo.
Zarrillo says the outcome will impact millions of gays and lesbians who also want the right to marry. With the court date just around the corner, Zarillo and Katami say they are excited, nervous and hopeful they can soon exchange vows before their families and friends.
"We feel very confident walking into that room with a sense of gratitude saying thank you for taking this so seriously, because people's lives are at stake," Katami said.
After Tuesday's hearing, the court will have several weeks to decide the case. A ruling is expected by the end of June.