Just one.
Reagan versus Carter.
Originally Posted by waverunner234
And how many went the other way? Two?
It's not a very large sample, so what does it prove?
Also, does it count if two Democrats (Truman and Johnson) refused to run again because the handwriting was on the wall and they know they would lose? They were having difficulty getting their own party's nomination, let alone winning the general election.
Since both were succeeded by Republicans that would make it three, not one.