The chief justice prior to our current chief justice (Rehnquist) wrote a memo as a clerk arguing against the holding in Brown v Board and bought a house in a neighborhood where it was illegal to sell homes to Jews while he was on the supreme court.

A huge amount of our current law was built by segregationists.

The last confirmed klan-connected lynchings in the US happened in the early 1980s, so possibly within your lifetime depending on age. If not then almost certainly your parents'. We mostly stopped using the term around then, but they didn't stop happening then either.

The south had plenty of politicians in open defiance of desegregation and integration, explicitly saying they would resist the tyranny of the federal government.

The tyranny of being forced to treat black people equally.

Countless communities across the US chose to destroy their infrastructure and amenities (specifically community pools) rather than allow their families to mingle with black people. There's an entire, well documented era of "white flight".

It's a common refrain by conservative voters that "The democrats abandoned the blue collar worker", but note they've been saying this for decades, so the ones that claim "identity politics" are the reason are wrong. Meanwhile they adored Reagan's fiscal policy, which was adopted wholesale by democrats after Reagan's landslide election proved any other fiscal policy was unacceptable to Americans. So nope, that also can't be what people mean by "abandon blue collar workers".

If you follow those claims back, they are from the civil rights era.

When people say "Democrats abandoned the blue collar worker", whether they realize it or not, they are saying "Democrats abandoned the WHITE blue collar worker by supporting black equality and integration".

This is evident if you look at the Democrat politicians who moved to the Republican party between the civil rights era and Reagan, and why they did so. They specify the civil rights act. Strom Thurmond openly switched to the republican party claiming that the Democrat's support and passing of the civil rights act and voting rights act meant they "no longer represented people like him"

This is also clear if you understand the history of black people in the south. It was a core part of southern "heritage" and history that white people were inherently superior to black people. It was a common topic of Sunday sermons during the civil war era for pastors to remind their congregation that it was God's Will that the black man be enslaved by the white, since they were barbarians and the White man was supposed to guide them. This is not an exaggeration.

"History not hate" is a contradiction, because the history WAS hate. Casual, institutional, systemic hate.

Republicans and conservative states have endeavored to not teach this, for decades. People in the south are genuinely taught that the North started the Civil War (outright false), that slavery wasn't the issue (False, several states explicitly submitted documents saying their reasoning for secession was to protect the institution of slavery), and that it was a "state's rights" issue (False, the slave states did not care about states rights, as they attempted to enforce Slave Catching laws in Free states by using federal authority, ie the exact thing they were critiquing the north for, and more importantly, the Confederate government openly talked about dropping the Facade of "states rights" now that they had their own government and could just install an authoritarian system that guaranteed slavery as an institution).

You can read all these Confederate government documents yourself. They were not shy about their intentions because it was a genuinely held belief that the white man was better than the black man.