Same-sex marriage supporters demonstrate in front of the Supreme Court on March 27, 2013 in Washington, DC. The rights of married same-sex couples will come under scrutiny at the US Supreme Court on Wednesday in the second of two landmark cases being considered by the top judicial panel. After the nine justices mulled arguments on a California law that outlawed gay marriage on Tuesday, they will take up a challenge to the legality of the Defense of Marriage Act (DOMA). The 1996 law prevents couples who have tied the knot in nine states -- where same-sex marriage is legal -- from enjoying the same federal rights as heterosexual couples.