Mr. Perlberg is part of a diaspora of gay Americans who have found they had to uproot and leave the country to continue to live with foreign partners. And this year, binational gay couples like his are a new — and controversial — focus of the debate in Washington on an ambitious overhaul of immigration laws. In a blueprint that President Obama presented last month, he pledged to give citizens, and also immigrants who are legal residents, the ability to petition for a green card for a same-sex foreign partner, if they can show they have “a permanent relationship.”

The Supreme Court will also take up same-sex issues this year, with hearings in March on two cases that challenge the definition of marriage as being a union between only a man and a woman. One case deals directly with a 1996 statute, the Defense of Marriage Act, that prohibits the federal government from recognizing same-sex marriage and governs the exclusion of gay couples from visas and other immigration benefits.

The politics of same-sex marriage are rapidly shifting, with polls showing Americans viewing it increasingly favorably but still divided. Many Republican voters strongly oppose it. Leading Republican lawmakers have questioned whether Congress should include such a hotly disputed issue in the debate when it will also wrangle with giving legal status to 11 million illegal immigrants.

“There are so many other, bigger issues the Congress has to resolve in immigration reform before we would even get to a point where we would be discussing a change to a longstanding policy like this,” said Senator Charles E. Grassley of Iowa, the highest-ranking Republican on the Senate Judiciary Committee, which is working to prepare immigration legislation.

The restrictions in the marriage act, known as DOMA, have a direct impact on Americans with foreign-born spouses or partners who want to live in the United States.