WASHINGTON — As the political debate over whether to include protections for same-sex couples in immigration reform heats up in the Capitol, the real control over what's going to happen with the issue likely rests with the Supreme Court.

Because the Defense of Marriage Act bars the federal government from recognizing same-sex couples' marriages, binational gay and lesbian couples — those where one partner is not a U.S. citizen — have been denied the ability to seek a green card that straight couples have been eligible to obtain for their spouse in a similar situation.

The legislation aimed at addressing this issue is the Uniting American Families Act, and it would create a new category, called "permanent partners," that would make same-sex couples eligible for green cards. The "Gang of Eight" senators did not include the measure in their immigration reform bill, but LGBT advocates have been pressing for Judiciary Committee Chairman Patrick Leahy to add the provision into the bill during the committee markup, which is slated to begin May 9.

And, although the focus this week has been on the claims by some Republican senators that inclusion of such protections would doom the immigration overhaul bill, little has been said about the Supreme Court — which is considering a case that could strike down that part of DOMA that bans recognition of same-sex couples' marriages, Section 3.

If that provision is struck down, married gay and lesbian couples are expected to be eligible for the same green card petitions as straight couples. The decision also could make the current language in UAFA inapplicable to same-sex couples.

Asked about this issue Thursday, Lambda Legal's deputy legal director, Hayley Gorenberg, told BuzzFeed only, "We will continue to push for UAFA until we are absolutely sure we don't need it. And of course the demise of DOMA section 3 will reduce harm to families but will fall far short of eliminating it."

She continued, "Same-sex couples still can't marry in forty states. And to assume traveling elsewhere to marry will solve the problems of a low-income couple in a southern state, for example, would be to disregard their lived reality and resources."

Under the current version of the UAFA legislation, however, a permanent partner is defined as someone in a committed relationship and "unable to contract with that other individual a marriage cognizable under [the Immigration and Nationality] Act."

As Lavi Soloway, a prominent immigration attorney who works on same-sex couples' cases and co-founded Immigration Equality and The DOMA Project, told BuzzFeed, "When we crafted the definition of 'permanent partner' that is the centerpiece of UAFA, our goal was the same then as it is today: to remedy the problem caused by the inability of same-sex couples to enter into marriages that would be recognized for the purposes of our immigration law."

With Section 3 of DOMA gone, however, same-sex couples' marriages would almost certainly be recognized under the INA. If that happens, the UAFA provision — even if enacted in to law — likely would no longer have any effect.