Although we can count the number of states that grant legal marriage to same-gender couples on one hand and still have fingers left over, legal marriage between people of the same gender exists in the US. However, the US Census has announced that, for the 2010 census, it will list all same-sex couples as "unmarried partners" regardless of their marital status.
The justification for continuing to make same-sex marriages invisible is the 1996 Defense of Marriage Act (signed by then-President Clinton) that allows, or really mandates that the federal government ignores same-sex marriages sanctioned by states. Can you believe this political discrimination has continued for 13 years now? Well, considering Clinton signed it in, and then we had 8 years of Bush, I suppose that's not really all that surprising.
Visibility or invisibility in the Census has great political and social consequences. For example, the 2000 census has made visible the large number of people that are multiracial/ethnic - a known fact, but the statistics of just how many people identify as such is powerful. Although the count of the number of same-gender partnerships is helpful, namely for LGBT groups like HRC and the National Gay and Lesbian Task Force, as well as for research...
