to be fair, theologically speaking the old testament law has been replaced by new testament covenant, so it's really only fair to ascribe NT beliefs to supporters of the amendment
I hate this argument. If the OT is invalid, why even subscribe to the entire bible? Why have the OT IN the bible? If OT law is invalid, why is it EVERY Christian references the 632 commandments (although, they typically think there are only 10)? If we're saying the OT is no long valid as a reference for moral guidance, then let's just toss it out. But no, we can't, because that takes away the creation story and the fall, both of which the religion hinges on. So, instead, let's pick and choose which parts of the bible we don't like. Jesus NEVER said the OT law is invalid. He actually endorsed it. Paul, a man who CLAIMED to have a vision of Jesus, said the OT law is no more and by "faith we are saved". Not Jesus.
So, you see, most Christians aren't Christians. They're Paul-inians.