It’s not revisionist history, he’s actually correct. The political parties are just shells, the constituencies move around through the years. Rather than focusing on the party names the key is to focus on a constituency like social conservatives. Prior to LBJ, social conservatives were Democrats but since then they’ve become almost exclusively Republicans. Strom Thurmond is a great case in point. We’re in the middle of another major reshuffling of the parties and their constituencies now with Trump’s Republican Party.