The “Southern Strategy” was used by the Republican Party in the 1960s and was the biggest cause of the party switch

Southern Strategy - A campaign tactic used by the Republican Party, but primarily Nixon and Goldwater to flip the south by appealing to white southern democrats using covert racism.

I’m going to add the stipulating that the Sources point should be given slightly more consideration as this is a debate that relies heavily on sources, not like a philosophy debate. However it is still up to voter discretion how that point is awarded or if it is at all.