If you know anything about the history of punk music and east coast hardcore, Ian MacKaye was clearly one of the most principled people in the scene, and a genuinely good and decent person. So it's really weird to hear that people ever got the weird idea that he was pro-racism or something.
Then again, The Dead Kennedys had to make "Nazi Punks Fuck Off" because they were sick of their shows being infiltrated by the wrong kind of skinheads.
I know a lot of people that are quite overall politically liberal that feel this way. I know a lot of people that get upset at the idea of inmates being given "free" educations in prison because they still have student loans 20 years after school. People that support the ideas of helping people up, that are fully on board with LGBTQ+ rights across the board, think DEI is a good idea, think it's critical that women have bodily autonomy, and so on, but still have a knee-jerk reaction to things that they don't fully get, or haven't had explained to them.
I don't know if he meant the song that way, or what. I do know that the people coming into the White House in a few months aren't likely to make things any better for people like him. Or people like you. Or people like me.