Racism is too large a problem in the US to be constrained to a single political party unfortunately, and at no point have I defended the Democrats so I don’t think what I’ve been saying and your feelings of it conflict.
The party platforms switched (largely) due to the platform FDR ran on. Prior to that point, Democrat platform was centered around smaller, limited government.
https://factmyth.com/factoids/democrats-and-republicans-switched-platforms/
However it wasn’t as clean as a single point in time you could point at and say “here, and these policies”. There was no handing over of anything and it wasn’t a cut and dry swap.
This is why a lot of Republicans will argue that the swap didn’t happen, because it was more like an evolution of stances over time with a few big notable shakeups and not really possible to pinpoint.
The source I provided above goes into some key points in history that serve as examples of how the parties switched platforms if that helps to understand it better.
One thing is clear though: the party of Lincoln and today’s Republican Party are similar only in name. For the most part, the same is true for Democrats. They are no longer the same party they were in the time period the other user continues to mention.
This is probably in my top 3 favorite Bo songs , especially the latter bit:
Full Song