You were mighty specific at limiting those who changed parties to federal officeholders. How many Republicans came with Strom Thurmond, for example when he switched? Democrats did become Republicans in droves in 1927 after the Great River Flood when their Party became a little less white, in 1948 after Truman integrated the armed forces, and especially during/after the civil rights movement. Your suggestion that race wasn’t even an issue until the 1990s is ludicrous. Ask Abraham Lincoln, or better yet, read the transcript from the Lincoln/ Douglas debates, which were all about race..