"41 states prohibit same-sex marriage. But only 20 of those 41 states have filed briefs in support of the constitutionality of Proposition 8."

"Indiana is the lead party on a brief for 19 states, and Michigan filed a brief of its own."

Compare this level of state participation with, for example, the amicus brief filed by all 49 other states in Maryland v. King (to be argued February 26), in support of Maryland’s argument that a state does not violate the Fourth Amendment by collecting and analyzing the DNA of persons who have been arrested for, but not convicted of, a criminal offense....

It is further significant, I think, that in 12 of those 21 non-filing states, constitutional amendments prevent the recognition of same-sex marriage via the ordinary political process.  All but one of those amendments was ratified from 2002 through 2008, in anticipation that popular majorities might soon support a change in state law...