I don't think we have the time to wait 20 years for them to change. Once they get control of the election rules they will remain in power permanently.
Also, the core Trump people are fanatics/true believers and they are never going to "see the light."
Lastly, the party-primary system gives the most extreme members of each party power out of proportion to their numbers. The extreme right wing and religious fundamentalists are going to control the GOP for a very long time.
You can't outwait a strong group determined to kill you. They will finish the job while you are waiting for them to go away.
Could the Jews have fixed the Nazi problem by waiting for them to go away? No, they couldn't have.