IMHO:
The reason The GOP went wild-eye right is two fold: First they realize they have no policies popular with a majority of American people at the national level, and they have accepted that they can never legitimately win enough elections, under the system of government in place in America today...Therefore... they want to destroy that system.
The second is a product of the massive Russian corruption of the GOP.
When Russia hacked the DNC in 2016, they also hacked the GOP, and now hold serious compromat on all the GOP's very, very, dirty laundry.
We all witnessed the Never-Trumpers turn into Trumphumpers soon there after.
The vile Facistas who suckled at the teet of right-wing radio ala Rush Limbaugh and all the Rush wannabees who speak for White Nationalists, (many, since they were kids) came along for the bullying fun; while the Christian Evangelicals, KKKers,and Nazis all came along for the BarB-Q, violence and bigotry available under the guise of main-stream politics.
I'm for that.