Why are republicans who are not even MAGA supporters brainwashed?

There are many MAGA-hating Republicans who for some unknown reasons refuse to acknowledge the role of their party in creating the monster called MAGA. They have the audacity to blame Democrats for why MAGA exists. I feel like it will take at least 50 years to correct all the ignorance, stupidity, lies and hate that has been promoted in the Republican party. I know this is a centrist sub but centrists must do their party in ignoring candidates from a party that is deeply flawed as the Republican party. The Republican party promotes dangerous rhetoric and myths to naive people especially vulnerable white southern Americans