I've going back to Michelle Alexander interviews and articles from 2016, which reminded me of points she made. Back then I was angry with her, now I realize she how true her proclamations were.
https://www.thenation.com/article/hillary-clinton-does-not-deserve-black-peoples-votes/

So with that, just addressing your first point, what leverage did the evangelical right have, which allowed them gain and retain all of the power they continue to wield?