I don't think what we see today in the GOP began with him. It started when Rush Limbaugh came onto the scene. He was the original daily manufacturer of anger, fear, and unapologetic hate for anyone not Republican. It's not that this didn't exist before him, it obviously did, but not on a daily basis. Limbaugh pioneered the every-single-day multi-hour blitz of half-truths and outright lies, taking advantage of Americans' general trust in the media.
But he sounded legitimate. He had the voice of a newscaster and spoke in simple language that was easy to comprehend, and he must be telling the truth because hell, he's nationwide. There was none of this business about nuance, complicated legislative issues, the complexities of different circumstances, historical considerations, or anything else that would take the focus off of the simple message of "America is great, you're an American, so you're great; but there are those actively plotting to take it all from you--and here's who they are." It's all very black and white with not a lot of need to think. All one knows is that what they're feeling has been articulated by a voice on the air.
Others quickly followed because he was so successful and it took less than a decade before there were a lot of nationally syndicated copycats on the radio as well as an entire news network devoted to broadcasting in the Limbaugh style.
Dubbya was the half-wit legacy beneficiary of it all.
Trump is the ultimate culmination of it.
