James Taranto makes a good point in today's WSJ--those who argue against the FMA by claiming that it interferes with states' rights are on dangerous ground. Even if the FMA fails, few states will enact gay marriage. In order to overcome that hurdle, the only argument is that, despite states' rights in this area, bans on gay marriage violate the equal protection clause of the Constitution. The better position is that the FMA is discriminatory, not that it violates states' rights.