American communists have a extreme fetish for the American Civil War, and especially with Reconstruction. They project modern politics onto it very, VERY hard. They worship the Union and white wash it as some sort of progressive beacon of hope and glory that was literally gonna lead us all to gay luxury space communism and the Confederates as all being the establishment and reactionaries and evil capitalists and so on and so forth.
It's why they are so desperate to destroy the legacy of the Confederacy. They see it as a prelude to their own revolution, so they need to get it done. It is why they refuse to allow it to have a nuanced discussion and explain how both sides were racist as all hell but the issue was about states rights to slavery and how to deal with it. When they speak of the hate they have of Dixie they are actually hating on the Yankees just as much, just through a lens.