The nine judges of the US Supreme Court will decide next week whether to consider the constitutionality of same-sex marriage – a keenly awaited choice that will have far-reaching implications for thousands of legally married gay couples across the United States.

Activists are hoping that shifting public opinion on the issue, most recently demonstrated by election-day victories in all four states where same sex-marriage measures were on the ballot, will convince the judges to take on the issue.

Up for decision is a set of cases relating to the Defense of Marriage Act (Doma), a 1996 law which states that every time any federal law refers to marriage, it means only that between a man and a woman. Same-sex couples who are legally married in one of nine states or Washington DC are thus denied the benefits or opportunities afforded by marriage to opposite-sex couples.

Five federal courts have ruled that Doma is unconstitutional. The Supreme Court could decide to take on one or more of these cases. The judges will also decide whether to consider an appeal from supporters ofCalifornia‘s Proposition 8, a voter-approved amendment to the state constitution which seeks to ban same-sex marriage. Another petition before the justices relates to the state of Arizona, which is seeking to revive a state law that is similar to Doma.