Last week, Rhode Island became the 10th state to legalize gay marriage. Delaware's state Senate is voting Tuesday on a measure that narrowly passed in the state House that would also legalize same-sex marriages.

Earlier this year, the Supreme Court heard a pair of cases challenging the constitutionality of a federal law that prevents the government from conferring benefits on gay spouses and a California law prohibiting gay marriage. Gay rights activists hope the Court could rule in a way that might legalize gay marriage in more or all 50 states.