[Ancesthntr]

2)Congress has the power by a 50.1% vote to pass a law defining marriage, then remove authority for any federal court, including the supreme court, to have any jurisdiction relating to the law, or even the topic of marriage in general. - that is doable

The exact opposite can and will happen whenever the political winds change. The reason for a Constitutional amendment is to make certain that the law doesn't change so rapidly. A society with no definite laws is an anarchy, and since people inherently don't like to live in such a state, then such a society would be ripe for a dictator or oligarchy.

[GrandEagle]

I do understand your point. We are currently ruled by an oligarchy and have been for many years. Congress, the most powerful branch of our Government, refuses to do it's job.
I'll agree that a very good case can be made for the amendment but I am far more fearful for the current ruling oligarchy having any legal basis to have an opinion on marriage. At least what they are doing now is Illegal, and we do have recourse if enough people choose to take it; and that is to require that our congressmen do their job
We should impeach and remove from the bench judges who had expresses their disdain for our Republic by expressing their intent to put us under the jurisdiction of other countries rulings.
We should vote out any congressmen who vote for a law that deals with a subject that "we the people" have not given them authority to legislate on.
This two party system has killed our republic. The point has become having your "side" win instead of what is legal to do by our Constitution.
While time is quickly passing where we will have the capability to regain a Constitutionally functioning government, we still do have the means.