A lot of Reagan’s “supporters” did all they could to destroy him till it became apparent that he was beating them. Then they latched on like leeches in a mudhole and have claimed him to be a middle of the road moderate ever since.
He wasn’t perfect but his biggest fault is that he was too trusting.
Lot of Democrats came with him, they are affectionately known as RINO's here.
Call me paranoid, but I wouldn’t be surprised to learn that there have been “sleeper cells” of leftists in the GOP, waiting their time to turn it to the left/destroy it from within. Why not, they’ve done it with every other institution in the US, saving the hardest nuts to crack (the Christian church, the military, the opposition on the right) for last.
“A lot of Reagan’s “supporters” did all they could to destroy him till it became apparent that he was beating them”
Then you have the great Jesse Helms, who supported Reagan from the very beginning. Porky Pig Rove was always a moderate, who first supported Gerald Ford over Reagan, then supported George HW Bush over Reagan. Both were pro-abortion, moderate republicans, and that is exactly what Rove is.