
Obama aides emphasized that he has opposed similar state bans in the past. They said Obama does not support gay marriage but believes that federal and state constitutional amendments banning it can also threaten rights that couples have under civil unions and domestic partnerships, which Obama does back.

Obama quietly made his stance known in the letter to the Toklas club, a California gay rights group. His position comes as a shift for Democrats, as 2004 presidential nominee John Kerry backed amendments to ban gay marriage in some of the states in which he campaigned.
