Would Reagan have been as successful politically had he remained a Democrat?

[The Right Honourable Martin Brian Mulroney PC CC GOQ]

The short answer is no.

The long answer depends on what you mean by "remained a Democrat". If, for example, Reagan had his ideological shift to the right but remained in the Democratic Party, there's not a flicker of a chance that he could ever have been president. Conservative democrats did exist in his day, but the national Democratic Party was dominated by liberals. Remember, Reagan's views were considered too right-wing by many Republicans, let alone Democrats.

I don't think he could have even been the Governor of CA as a conservative Democrat - while California was more conservative in those days than it is now, CA Dems were firmly in the liberal wing. As a conservative Democrat from California, the highest heights you could imagine him reaching politically would be as a congressman.

If you mean he remained a liberal, or at least moderate, his chances go up slightly, but not by much. I mean, let's say everything about Reagan remains the same, but instead of emerging as a hardcore anti-communist Goldwaterite, he emerges as a high-profile liberal activist in the 1950s and 60s. Or not even a liberal activist, potentially just a moderate, middle-of-the-road Dem. I can't imagine that he could have won the Presidential nomination as a Democrat in the 1960s, because that would require him to upset the Kennedy-Johnson-Humphrey establishment as an outsider, and I don't see how that could have happened. You could imagine he becomes a Governor or Senator as a Democrat, and maybe shoots his shot in 1972. In a scenario where he is Nixon's challenger instead of McGovern, he probably would have done better, but not enough to win.

The hypothetical Democrat Reagan would have his best shot in 1976, when the American public was looking for an outsider, and instead of the peanut farmer from Georgia, that outsider happens to be the actor from California. He was more charismatic than Carter, no doubt, so that could have helped against Ford. But remember, Carter absolutely swept the south and barely beat Ford - a Democrat Reagan would not have swept the south, and I'm not sure he could make up for it with the west and midwest.