So we are finally getting a real federal court challenge to DOMA by Massachusetts. On behalf of its 16,000 married gay couples, Mass. is asking what purpose the federal government has in denying them equal rights with other persons validly married under state law. The case has all the earmarks of a winner. It's the right plaintiff and the right argument. Why do I say this? Because the challenge being brought in California to Prop 8 is based on an equal protection argument that says "all persons have the right to marry." That is politically more difficult and requires a bigger ruling. The Mass. challenge, by contrast, is an equal protection argument for already-married persons. The Court can rule more easily that nothing requires a state or the federal government to marry two persons of the same sex to each other, BUT that where a person is legally married in a state to another person of the same sex, the feds, at least, must afford such persons equal treatment with other married persons. I expect Justice Kennedy will write a majority opinion striking down at least that much of DOMA.