The Democratic party WAS racist- primarily made up of white southerners. And Republicans were far more comfortable with at least relative equality. (Let's face it- no one was scoring an A+ on that mark for most of US history)
Presumably you know about the
Southern Strategy. During the 1960s, the Republican party intentionally adopted racist policies and rhetoric to get more support from white voters in the South because they were getting slaughtered there. Nixon and Goldwater led the charge on this. And it continues to this day.
So those very racist white southerners who used to control the Democratic party started gradually becoming Republicans, and those Republicans who were more liberal on issues like race became Democrats. We've been watching that process play out our whole lives, and the GOP increasingly operates as an ethnonationalist party- which is and was intentional.
Yeah the woman in this appears not to know that history (Though it looks very much like it could actually be a mash up of two different videos btw) But that doesn't, in any way, mean that Democrats are the "racist" party and Republicans are still the party of Lincoln.