The Supreme Court is wading into the fight over same-sex marriage at a time when public opinion is shifting rapidly in favor of permitting gay and lesbian couples to wed, but 40 states don't allow it.
The court's first major examination of gay rights in 10 years begins Tuesday with a hearing on California's ban on same-sex marriage - Hollingsworth v. Perry.
On Wednesday, the justices will consider the federal law that prevents legally married gay couples from receiving a range of benefits afforded straight married Americans - United States v. Windsor.
People have been waiting in line - even through light snow - since Thursday for coveted seats for the argument over California's Proposition 8.
Nine states - Connecticut, Iowa, Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont, and Washington - and the District of Columbia allow gay marriage.