If they outlaw it in Mass., they will find another state, and they will convince the court to enforce "full faith & credit" to "federalize" gay marriage. SCOTUS will ignore the Defense of Marriage Act, as it is mere legislation vs. "full faith & credit" which is in the Constitution.
You don't take a knife to a gunfight.
We need less federal control, not more.
And if there was to be an amendment I think it should be to remove the requirement that states must recognise each others marriages.
Then states can do what they want and suffer or enjoy the consequences.
As they should.
There is no question that the Federal Constitution requres 50-state recognition of Massachusetts gay "marriages", and that DOMA, to the extent that it contradicts this plain fact, is unconstitutional.
DOMA will be struck down the first time it is challenged, probably within three months.
I hate the idea of an amendment (and it will rapidly become unmanageable, as court usurpations proliferate)-but it has to be done.