Here's where things get interesting and technical. In the paired Massachusetts cases--Gill v. OPM, brought by GLAD, and Commonwealth of Massachusetts v. Department of Health and Human Services, brought by Massachusetts Attorney General Martha Coakley's office--the US government had already argued in favor of DOMA. But the Justice Department says that it did so because the First Circuit had previously decided that sexual orientation could be reviewed on a "rational" basis: any old justification would do. The Second Circuit has never suggested that it knows what standard to apply to cases involving lesbians and gay men. So the Department of Justice had an obligation, by March 11, to tell the court what it was going to argue.