The Obama administration has dropped its backing of the 1996 Defense of Marriage Act, or DOMA, which denies federal recognition of gay marriage. On Tuesday, the White House said it would no longer defend the measure in two ongoing lawsuits against it. The law is the last major federal statute to openly target gays and lesbians, following last year’s repeal of the “Don’t Ask, Don’t Tell” policy, which bans openly gay people to serve in the military. The administration had previously maintained it opposed DOMA but was obligated to defend it as an existing federal law.