A federal appeals court in New York has become the second in the country to rule the Defense of Marriage Act unconstitutional. This is a key legal breakthrough, and it's an even bigger deal if you consider what the landscape might look like in a year or so.

The 1996 Defense of Marriage Act (DOMA) defines marriage as a union between a man and a woman, enshrining into law the federal government's non-recognition of gay marriage. Thursday's decision is important because it relies on a sweeping rationale for invalidating DOMA.

As Ian Millhiser, a senior constitutional policy analyst at the Center for American Progress Action Fund, explains, the conservative judge who wrote Thursday's ruling "is not simply saying that DOMA imposes unique and unconstitutional burdens on gay couples, he is saying that any attempt by government to discriminate against gay people must have an 'exceedingly persuasive' justification. This is the same very skeptical standard afforded to laws that discriminate against women."

Millhiser goes on to explain that if Judge Dennis Jacobs' "reasoning is adopted by the Supreme Court, it will be a sweeping victory for gay rights, likely causing state discrimination on the basis of sexual orientation to be virtually eliminated. And the fact that this decision came from such a conservative judge makes it all the more likely that DOMA will ultimately be struck down by the Supreme Court."

Now consider that the decision came the same day The Post released a poll finding that a majority of likely voters in Maryland support a referendum upholding a state law legalizing same-sex marriage. If that passes, it will be the first time gay marriage has been ratified by popular vote. Voters in Maine and Washington state will vote this fall on similar referendums, and polls suggest those may pass too.

If all three pass, same-sex marriage would be legal in nine states. And if DOMA is ruled unconstitutional, the government will have to accord full federal recognition (and benefits) to all the same-sex couples that marry in those states.

The next step would be a ruling that Americans have a constitutional right to same-sex marriage in every state. A court ruling on California's Proposition 8, which said same-sex marriage is not legal in that state, has been appealed to the Supreme Court, so the broader issue could come before the justices next year.

In any event, it became more likely Thursday not just that same-sex marriage will be legal next year in a wide swath of states but also that gay married couples in all those states will enjoy full recognition from the federal government.


To read commentaries about Minnesota's proposed marriage amendment, go here.