They are not Moslem style polygamists and will shed the habit when they settle in the US. Their primary gooal will be to become Americans and that excludes polygamy even if the USSC legalizes it.
My friend, I am afraid you are speaking to a brick wall. Unfortunately, too many Americans are negligent of other cultures and therefore are unaccepting of those which are different.
It is ironic that I meet many new immigrants (legal) that seek to be more American, than most natives I know.