The propaganda machine from the left is trying to create another narrative to protect itself from its own sins of the past. Abraham Lincoln was a Republican. The Democrats were the ones who wanted to perpetuate slavery in the 1860's. When the Republicans freed the slaves the Democrats threw a hissy fit and tried to divide the country. This led to a civil war .
During the civil war over 600,000 men died. Republicans and many freed slaves accounted for half that total. They died to unite the country and maintain freedom for the slaves. The other half were Democrats who double down, even to death , to divide the country and maintain slavery. That is the biggest tell in the history of American slavery, yet this is ignored by the Democrat scam theory. They blame everyone but themselves. The blood is there or proof. All whites did not to cause this problem, just the Democrat whites. White Republican paid their debt already in blood. This is called reality race theory. The Democrats doubled down in blood. This is the debt not yet paid.
The Democrat party should have been exiled and dissolved for its role in trying to divide the country and trying to perpetuate slavery . The Republican were merciful and left cancer in place. Did the Democrats learn anything from this? They used that power to develop legal means to put down the blacks. They were not giving up. The KKK was an intimidation army like ANTIFA today, but worse. Segregation and Jim Crow laws was the fruit of their efforts. Before Hitler rose to power, he and his propaganda team learned from the Democrats how to legally make any race the villain and applied it to the Jews; legal systemic racism.
The only way to make this issue go away is the Democrat party cancer needs to be dissolved. It heritage comes with its long history of inhumane behavior. A new party can form from the ashes with a clean slate and no baggage to hide with scam like critical race theory.
There are many different ways to look at and interpret U.S. history. The Democrats were the party of Andrew Jackson, although one interesting piece of history was that he was foursquare against the idea of any Southern states seceding from the Union. He said he would hang them like traitors if they ever did such a thing. The Democrats were not all of one like mind, and they had the same regional divisions which were evident in the country itself.
The Abolitionists were not all of one like mind either, even if they all agreed that slavery must end. The industrialists in the North also had economic motivations for opposing slavery. There were, essentially, two competing economic factions in play. The plantation economy of the South, which was largely agrarian and dependent upon export of a few commodities while relying on imports for manufactured goods (which is why they were also big advocates for free trade, something we see more prevalent among capitalists and Republicans these days). The Northern economy was different, as they wanted more industry and a diversified economy which would rely less and less on imports, which is why they tended to favor tariffs.
To be sure, there were some Abolitionists who were quite passionate and sincere in their desire to end slavery and promote human rights, racial equality, and justice. Many were devout Christians who believed it was a righteous cause, although there were Christians in the South who also used religion to argue for their cause, which was the opposite of that of the Abolitionist Christians. Strange how these things work out.
Both parties still advocated for expansionism and supported racist, segregationist policies - not only in the South, but also in the West with Indian Reservation system, along with racist policies which affected Latinos and Asian-Americans. The Republicans were not a party of humanitarians, and given their strong support from industrialists from the very beginning, they've been in the back pocket of big banking and corporate America ever since. Teddy Roosevelt broke that mold a bit, but even he was seen as a bit of a maverick within his own party.
After the Civil War, the Democrats were still strong in the South, but the Republicans maintained primacy over national politics. Strictly speaking, they could have sent troops back to the South to crush the KKK and enforce the Civil Rights mandates of the 13th, 14th, and 15th Amendments. They could have mandated what the Democrats ended up mandating in the 1960s when they ended Jim Crow laws and passed the Civil Rights Acts (although the Southern Democrats opposed it). But other Democrats, such as JFK and LBJ, supported it. The Republicans could have done all that in the Postbellum era when it was clear what the KKK and their state/local leaders were doing. They could have reined in some of their generals out West, but instead, they ordered them to "pacify" the region. They supported the idea of "separate but equal," and they even practiced it in the Northern cities to which many freed slaves migrated to - although perhaps not quite as blatant as the Jim Crow laws of the South.
So, whenever I hear this idea that the "Democrats are the party of the KKK," that's only a half-truth. The full truth is that the atrocities of the KKK occurred under mostly Republican administrations at the national level, who pretty much did nothing about it. Moreover, there are strong indications that they themselves shared many of the same racist beliefs as the KKK, as evidenced by the racist atrocities which occurred in the Republican-dominated North and Western United States. The only real difference is that some wore blue cavalry uniforms and others wore bedsheets.
And the bottom line is that all of this was done for profit, so that capitalists could make more money. Ideas like "Manifest Destiny" were just propaganda - just a bunch of hokum to dupe and pacify the white masses into going along with it. Capitalism is the true evil here, and racism is one of many consequences emanating from that evil. Racism is very much rooted in greed as it is hatred.
That's the thing to look at: We seemed to be on a decent course towards civil rights and justice in the 60s and 70s, which also included a strong anti-war and peace movement, as well as greater attention to the plight of the poor and working classes. All this changed when Reagan came in like a whirlwind and pushed his trickle-down ultra-capitalist ideas. That's when everything started to go haywire. That's when whatever progress which had been attained stagnated and went off in a different direction. Even the Democrats pretty much gave in and sold out. Both parties were growing out of touch, while factories shut down and our economy started to rest more and more on funny money. As a result, large sections of the populace are more economically insecure, along with being somewhat disgruntled and disaffected.