As the Supreme Court hears arguments Wednesday on the federal Defense of Marriage Act, one couple in New Jersey will be watching the case closely. It's not not just because they're gay, but because only one of them is an American citizen. 

Jason Grenfell Gardner and his partner, Yoann Ricau, have a fear of flying, but it's not about the time spent in the air. In 2008, Gardner had just moved back to the U.S.

Ricau, a French national, was making frequent trips to the U.S. as a tourist -- frequent enough that a customs officer could have objected.

"You do that thing where you watch the people from immigration and you try to figure out what plane they've come off," recalled Gardner recently of a wait in a Phoenix airport. "I waited an hour, I think, and finally he appeared -- I have no idea what took you so long ... But those moments are so, so gut-wrenching."

Ricau says he shares that anxiety every time he leaves the country for a vacation, or to visit his family in Europe.

"At the moment I step into the plane leaving the U.S., I already think about the time I'm going to have to come back," he says.

Gardner and Ricau met when they both worked in Estonia. Ricau moved in and they got a dog together.

"That was kind of the commitment," observes Ricau. The "commitment," named Maximillian, is now 13..

In a precarious position in New Jersey

They now live in a house in New Jersey. They also reside in the dead center of a series of court and legislative decisions, which will ultimately determine whether they can continue to live here together.

The couple got married in City Hall in New York City.

However, the Defense of Marriage Act, which defines marriage as solely between a man and a woman, governs federal law. Since Washington does not recognize their relationship, Gardner can't sponsor his husband for a visa.

Gardner's former employer does for now, with a work visa. In a rough patch, the company has had to furlough half of its employees. Things feel a little precarious.

If Ricau were to lose his job, he would have 30 days to leave the country.

On Wednesday, the Supreme Court will hear arguments in a challenge to DOMA. Professor Kermit Roosevelt, at the University of Pennsylvania Law School, says the "conventional wisdom" when you hang around with constitutional scholars is that the court will strike the law down.

"If you look at the pattern of the court's decisions over the past 15 to 20 years, there's definitely been a consistent increase in the protection they're according same-sex relationships," Roosevelt said.

DOMA challenge relatively incremental case

In one possible scenario, the court's swing justice, Anthony Kennedy, would probably cast the deciding vote in what Roosevelt describes as a relatively incremental case for the Supreme Court.

"This is not saying states have to let you get married -- it's just saying if you are married under the law of your state, the federal government can't treat you differently," he said.

This week, the court also considers the legal challenge to California's Proposition 8, a ban on gay marriage in that state.  Roosevelt says the justices are more likely to rule that states can set their own rules.

Since Ricau and Gardner's home state, New Jersey has civil unions but not marriage, they may have trouble getting federal recognition. New Jersey Gov. Chris Christie has vetoed same-sex marriage legislation.

Which brings us to another national debate that could decide the couple's future: comprehensive immigration reform.  The U.S. Senate is still working on the framework of an overhaul to the country's immigration system.

Moving on to immigration

Tom Plummer, a staff attorney with the advocacy organization Immigration Equality, says that if the Supreme Court upholds DOMA, his group's stakes in that fight would rise.

"If the Supreme Court was to make, what I believe would be, the wrong decision and uphold DOMA, it's really important for there to be some sort of relief for these families in comprehensive immigration reform," Plummer said.

President Barack Obama's immigration proposal includes a provision for gay couples.

Some Republican Congressmen, including Charlie Dent from the Lehigh Valley, support this inclusion. For others, it would be a deal-breaker.

The Rev. Gabriel Salguero, president of the National Latino Evangelical Coalition, says the group does not want to see immigration reform derailed by inserting another politically contentious issue. However, he said, he does not want that interpreted as a return to the culture wars of the 1990s.

He will also watch the high court closely.

Favorable DOMA ruling akin to lottery win

While in limbo, Gardner and Ricau say they try to live their lives as they would otherwise. They still can't imagine what it would look like if Ricau is allowed to apply to stay in the U.S. as Gardner's partner.

"That question," Gardner says, "for us is like asking if we win the lottery tomorrow.

"It's such a life-changing event. And it's a life-changing event that also gives you the freedom to do what you want to do," he said. "And so, whether it's winning the lottery or a positive Supreme Court decision, for us it's the same thing."

The Supreme Court's ruling is expected this summer. The immigration plan could be ready by then, or very well could stall in Congress. And gay marriage might even go on the ballot in New Jersey this fall.