clearheaded, they don’t out of respect for the civil laws of the states they live in
Wrong, I know of at least one Yemenite with living in America with two wives. But again, that’s phasing out. Yemenite women today in civilized countries would not stand for it.
One can always say the second wife is female freind living in the same house and be married to her according to halacha.
In addition if polygamy would be the accepted practice of frum Jews they would definitely be able to practice it under freedom of religion, as you yourself pointed out yesterday.
There is definitely another religious group in America other than the Mormons you mentioned practicing polygamy. I remember reading about it, I just don’t remember the name of the group.
But again, if it’s not the accepted practice of our times, it’s because Hashem willed it to be so.