LBJ said it…

“If you can convince the lowest white man he’s better than the best colored man, he won’t notice you’re picking his pocket. Hell, give him somebody to look down on, and he’ll empty his pockets for you.”

https://www.snopes.com/fact-check/lbj-convince-the-lowest-white-man/

He wasn’t advocating on it, but commenting on the Republican strategy and all the racist shit he saw down in the South