1- a list of politicians who switched from the Democrat Party to the Republican Party during the period of the Civil Rights Movement and the implementation of the Southern Strategy.
2- a mathematical analysis of that list which shows an inordinate percentage of Southern politicians making that jump as opposed to any other area of the nation.
3- a list of politicians who at the same time switched from the Republican party during the same period
4- a mathematical analysis of that same list and a comparison to show that it dwarfs the opposite list
5- representative statements from the architects of the Southern Strategy
Would all or a significant part of any of that constitute the proof you are looking for?