The US Supreme Court has struck down the Defense of Marriage Act , a 1996 law blocking federal benefits to same-sex couples and cleared the way for same-sex marriage in California.
"The federal statute is invalid, for no legitimate purpose overcomes the purpose and effect to disparage and to injure those whom the State, by its marriage laws, sought to protect in personhood and dignity,” Justice Anthony Kennedy wrote in the majority opinion. "By seeking to displace this protection and treating those persons as living in marriages less respected than others, the federal statute is in violation of the Fifth Amendment."
The court's 5-4 decision said the Defense of Marriage Act, known as DOMA, discriminated against same-sex couples as it denies equal protection to same-sex couples and was unconstitutional.
In the second case, the court said that it could not rule on a challenge to Proposition 8, a ban on gay marriage passed by California voters in November 2008, because supporters of the ban lacked the legal standing to appeal a lower court’s decision against it.
The US Supreme Court said a private party did not have the right, or "standing", to defend the constitutionality of a law, because it could not demonstrate it would suffer injury if the law were to be struck down and same-sex marriages allowed.
Their opinion leaves in place a ruling by a lower court, in San Francisco, that struck down Proposition 8; and will in effect allow same-sex unions to resume in the state.
Under the Defense of Marriage Act, same-sex couples who are legally married in their states were not considered married in the eyes of the federal government, and were ineligible for the federal benefits including tax exemption for health benefits for gay spouses and the right to petition the government for a green card. Not counting California, 12 states and the District of Columbia have authorised gay marriage.
US President Barack Obama, who announced a year ago he supported same-sex marriage, has "applauded" the court's rulings. He said in a statement: "This ruling is a victory for couples who have long fought for equal treatment under the law; for children whose parents' marriages will now be recognized, rightly, as legitimate; for families that, at long last, will get the respect and protection they deserve; and for friends and supporters who have wanted nothing more than to see their loved ones treated fairly and have worked hard to persuade their nation to change for the better."
He added that he has directed members of his administration to review "all relevant federal statutes" to ensure the Wednesday's decision is implemented "swiftly and smoothly."