No state (or other political subdivision within the United States) need treat a relationship between persons of the same sex as a marriage, even if the relationship is considered a marriage in another state.
The Federal Government may not treat same-sex relationships as marriages for any purpose, even if concluded or recognized by one of the states.
To drive the point even further, 37 states slowly but surely adopted DOMA as a state-wide regulation further amending state Constitutions. This appalling law tells the American people that it is OK to discriminate. That it is OK to recognize the LGBTQ community as less than equal. This same law, that the California Supreme Court deemed unconstitutional set the precedence for Proposition 8. This same law has nullified many rights that come with Domestic Partnerships. This law has nullified the heterosexual rights that come with Common Law Marriage. This law blurred the lines of separation of church and state even further. And this law, is one of many that President Elect Barack Obama has PROMISED to repeal in his "Open Letter to the LGBTQ Community."
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