Sen. Mark Warner announces gay marriage support

• Virginia Democrat joins growing list of politicians to support same-sex marriage
• Supreme Court takes up two high-profile gay-marriage cases this week
• Warner signed a legal brief urging justices to find federal law unconstitutional

Sen. Mark Warner of Virginia, a Democrat up for re-election next year, publicly announced his support Monday for gay marriage in a post on Facebook.

Warner's announcement comes on the eve of Supreme Court arguments on the constitutionality of California's Proposition 8, a 2008 voter referendum that banned marriage for same-sex couples.

Warner is among a growing list of politicians to announce their position as the high court takes center stage on the controversial issue. The justices will hear arguments Wednesday about the federal Defense of Marriage Act, which defined marriage as between one man and one woman.

"I support marriage equality because it is the fair and right thing to do," Warner wrote. "Like many Virginians and Americans, my views on gay marriage have evolved, and this is the inevitable extension of my efforts to promote equality and opportunity for everyone."

Warner joins Sen. Claire McCaskill, another moderate Democrat, who announced her support for same-sex marriage in a post Sunday on Tumblr. In recent weeks, other high-profile politicians — such as former secretary of State Hillary Rodham Clinton and GOP Sen. Rob Portman of Ohio — have publicly stated changes in their views to say they support marriage equality.

Warner is best known for his work on budget issues. This month, he was one of 40 senators to sign a legal brief to the Supreme Court arguing that the federal Defense of Marriage Act is unconstitutional.