Good point about their religion being legal. I was wrong about that. They have the right to practice whatever they want as long as it is not doing damage to another person in some manner. Everybody knows they are polygamous though down there it seems. It is odd there is no case for that yet, however.
But others have made the very good point that one third of the white population and two thirds of the black population also has men who father children with multiple women, and since these couples (or whatever they are) don't have State of Texas licensed marriages, what's the difference?