I'm sure it's theoretically possible to do poorly in a class because the teacher didn't like you, but statistically, it's got to be one of the most powerful red flags on a human. Steer clear.
There could be teachers who are fanatics about some political issue, and if you even hint you might disagree with them they'll try to lash out. I also recall some university level class (I didn't take it but a friend did) where religion was a topic and the professor intentionally set very loaded questions in online tutorials. While it's fair to ask people to question their own assumptions, it often seems the people most keen on this are ones who would become very irate if their own assumptions got questioned.
Perhaps that why some groups of people tend to gravitate to STEM, where teacher bias is less likely to have an impact.
Ah, the student didn't know one of the secret college hacks: Teachers with an ideological axe to grind are almost always the easiest graders, because they can be manipulated by dog whistles, and need to be liked. I got my best grades in the obligatory religion classes.
