Here's the full interview that you are referring to with Lee Atwater. Since it's becoming referenced more and more, it really deserves a full listen. I believe it is mostly misinterpreted, and I was guilty of that myself.
https://www.thenation.com/article/exclusive-lee-atwaters-inf...
Atwater was referring to the GOP Southern Strategy and how it evolved from 1954 to 1968. He wasn't referring to his strategies during the Reagan election in 1980. I believe he's gotten a bad rap for that. He graduated college in 1973 after that period.
Atwater: But Reagan did not have to do a southern strategy for two reasons. Number one, race was not a dominant issue. And number two, the mainstream issues in this campaign had been, quote, southern issues since way back in the sixties. So Reagan goes out and campaigns on the issues of economics and of national defense. The whole campaign was devoid of any kind of racism, any kind of reference. And I'll tell you another thing you all need to think about, that even surprised me, is the lack of interest, really, the lack of knowledge right now in the South among white voters about the Voting Rights Act.
https://en.wikipedia.org/wiki/Lee_Atwater
The South voted primary Democrat (southern democrat, there were northern democrats that were a different flavor) for 100 years, since 1860 because Lincoln was a Republican and Lincoln burned the South. I mean the South constantly voted majority Democrat up until about the civil rights era in the 1960s when they turned majority Republican. I'm sure you are aware, the South almost always votes majority Republican (in 2008 Obama won 3 southern states though). This shift was due to the Southern Strategy that Atwater was referring to, but did not implement himself. It's absolutely fascinating how much slavery and it's affects are part of this nation. I consider it our "original sin."
https://en.wikipedia.org/wiki/Southern_strategy