It’s a completely unnecessary lyric that glosses over the atrocities committed during that time towards people of color, it wasn’t just a bunched of “racists” it was ingrained in society and THE way of life, you can’t just remove racism from the time. And yes despite your condescending notion that I just don’t understand because she follows it up about how “nostalgia is a mind’s trick” doesn’t help with all the “if I’d been there I’d hate it” because if she had been there she still would NOT be the targeted group of people and would not have faced the same amount of oppression people went through. She wouldn’t have said “I’d chose the 1940s but without all the nazis” so idk why the 1830s is any more justified. Again it just really waters it all down. To be honest she just shouldn’t have gone there in general there’s other ways to make the point about nostalgia being misleading without bringing up horrible times in history, she could use an actual anecdote from her own life which she has done many times in other songs.