If the US would not have banned polygamy from the Mormon Church, they would currently be ruling the U.S.

In some cases some of these men had up to 19 wives and 64 children, just imagine that sort of exponential increase in the next generations. There are of course many outside of the U.S. that do still practice polygamy, but just an interesting remark that numbers can sometimes make a difference. Once you have a few hard core believers in whatever cause you are espousing, moving to another place and create your little Utopia seems to be the consensus way things have been done with these communities.