Bush was disingenuous to say "Reagan was liberal in the FIFTIES"...it's not that simple (and I think Reagan was the greatest president of the century, maybe ever.)
Reagan was a liberal in the 40’s, I heard video of him endorsing Truman and Hubert Humphrey (running for his first term in the Senate, he won) and attacking the Republican Congress in 1948. Started moving the right way in the 50’s (endorsing Ike while remaing a democrat) and I don’t think there is any doubt it’s cause he got an up close and personal look at commies in Hollyweird as SAG President.