I wish Thompson had clarified that a little better. In some of his comments it sounded as if he was literally opposed to the amendment. I know it isn't his position, but it left an impression that his stance on the HLA is no different than Hillary's or Obama's.
If I understand his position, he is trying to look as to what our Constitution would allow, and what would keep the spirit of that document intact. As someone pointed out he is strongly in favor of getting the Federal Government OUT of areas which aren’t Constitutionally allowable. Roe v. Wade was a decision which is in opposition to the Constitution. I would think that Thompson wouldn’t really think that an amendment was a good idea as it might change the spirit of the Constitution itself. Abortion should be dealt with at the state level — just as murders and sentencing for those murders are by the way. This remains the best, and completely Constitutional solution.