Yes, they teach that nonsense in intro political college courses and liberals repeat it to each other. Whenever somebody claims "all the racists went to the Republicans in the late sixties" I ask them to name them. Did Robert Byrd? Did Bull O'Connor? George Wallace? Al Gore. Sr.?
No. Why would they leave the Democrat Party to join the party that voted in greater numbers for the civil rights legislation? Of course they wouldn't and didn't.
All those guys were racist Democrats till the day they died. Byrd went onto to become the Senate leader for the Dems all the way into the 90s! Not the 50s - the 90s! Before he was the Democrat Senate leader he was the Grand Kleagle of the KKK!
Democrats are very gullible and will repeat what they are told without applying any logic or factual research.
“Whenever somebody claims “all the racists went to the Republicans in the late sixties” I ask them to name them.”
Another good line is to say “Oh, then how did George Wallace win 5 states and almost 25% of the popular vote in the 1972 Democrat primary if all the racists had joined the Republicans by then?”