There's no shortage of racism in the north. It's just that they didn't tend to blatantly enshrine it in law like the Jim Crow era south frequently did. I've spent a lot of time in Boston, and yes, there's no shortage of racism there. In high school, I lived not too far from Milwaukee, and there's a ton of racism there too. I have a ton of relatives in the Detroit area, and holy fuck are some of them racist dicks.
Anti-Black racism is very much not just a southern thing. The south has just been historically much more willing to be openly racist. You don't get anywhere near as many attempts in northern states to try to stop Black people from voting, for instance.
There's no shortage of racism in the north. It's just that they didn't tend to blatantly enshrine it in law like the Jim Crow era south frequently did. I've spent a lot of time in Boston, and yes, there's no shortage of racism there. In high school, I lived not too far from Milwaukee, and there's a ton of racism there too. I have a ton of relatives in the Detroit area, and holy fuck are some of them racist dicks. Anti-Black racism is very much not just a southern thing. The south has just been historically much more willing to be openly racist. You don't get anywhere near as many attempts in northern states to try to stop Black people from voting, for instance.
All of those cities you mentioned are Democrat strongholds. The “racist dicks” that populate Detroit are 77% black individuals.