The GOP has gotten increasingly radical since throwing in with Evangelicals and segregationists[0]. It accelerated with the Tea Party[1] wave which dragged the party further to the right, and keeps getting worse. We always came back from the brink because a shrinking number of cooler heads prevailed. Coming back this time depends on there being enough cooler heads.
[0] https://en.wikipedia.org/wiki/Southern_strategy
[1] https://en.wikipedia.org/wiki/Tea_Party_movement