My father was kind of a low level fixer in California politics.
He tended to vote Republican but regarded Reagan as a marginally literate moron.
After Reagantard reached the presidency in 1980, part of his obscene transfer of wealth to the rich brought on taxation of some of social security income.
One day I was talking to my father and kind out of nowhere he said, "Fuck Ronald Reagan."
I don't think anyone in the family voted RepubliKKKlan after that. For a lot of reasons. One of those reasons was his refusal to treat the rise of AIDS seriously.
I personally think they went through a meaningful shift from being evil but effective in their own way (in advancing their own agenda not in solving actual problems) to transparently stupid, and - genuinely unhinged Jewish space lasers, nuking tornadoes, drinking bleach, buying Greenland, and staring directly into the sun.
They've gone from cynically exploiting culture war nonsense to advance class war to believing their propaganda and losing the plot - I think the rise of the tea party was the inflection point.
I feel like Americans online throw this word around a lot more than anyone else. It's absolutely not an acceptable word to use here (UK) and I can't remember the last time I heard anyone use it.
In 2008 while railing against political correctness Sarah Palin, the dipshit republican vice presidential candidate, popularized the idea that it wasn't ok to use retarded as an insult.