What killed the democrats in the white south?

[RINO Tom]

Racism.

Just took 'em four decades to realize it, right?

LOL, that was one your hottest takes yet, chief!

[RINO Tom]

Civil Rights Policies. It begun with Truman's desegregation in the armed forces and went on to the liberal agenda of JFK and LBJ. Especially the latter's civil rights legislation. Democrats however remained relatively strong at the state level until the 1990s, when several prominent southern Democrats switched party. Reagan's conservatism gave the rest.

This is literally an explanation I'd expect in a sixth-grader's history textbook.  Disgustingly simplistic.  Democrats didn't just start championing themselves as being pro-civil rights after 1964, ya know...

Anyway, the post above yours is accurate.  Even in Presidential elections, older Southerners were MUCH more Democratic than younger Southerners into the 2000s (when, ya know, those folks started to die, not switch parties).

[RINO Tom]

Generational replacement, the abortion issue as Dems unified as solidly pro-choice, guns, NAFTA, and cultural tension

Not as sure about this ... it's kind of like the civil rights issue: if they were mad that a Democratic President signed the bill into law (which is clear with civil rights and debatable at best for NAFTA), why would they then flock to the party that, in both cases, had a Congressional caucus almost unanimously in support of both pieces of legislation?  IN THE SOUTH, I would argue the Republican Party (post-CRA and post-Goldwater) was just as associated with civil rights - and later free trade - as the local Democratic Party was.