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A file photo of a gay pride and an American flag hang from a shoulder bag during a demonstration outside of the Phillip Burton Federal Building on June 13, 2011 in San Francisco.
An appeals court ruled Thursday that the heart of a law that denies a host of federal benefits to gay married couples is unconstitutional.
The 1st U.S. Circuit Court of Appeals in Boston said the Defense of Marriage Act, which defines marriage as a union between a man and a woman, discriminates against married same-sex couples by denying them federal benefits.
The law was passed in 1996 at a time when it appeared Hawaii would legalize gay marriage. Since then, many states have instituted their own bans on gay marriage, while eight states have approved it, led by Massachusetts in 2004.
The appeals court agreed with a lower court judge who ruled in 2010 that the law is unconstitutional because it interferes with the right of a state to define marriage and denies married gay couples federal benefits given to heterosexual married couples, including the ability to file joint tax returns.
The court didn't rule on the law's other provision, which said states without same-sex marriage cannot be forced to recognize gay unions performed in other states.