He was a quality professor who gave full marks to answers that disagreed with what he presented in class, so long as the answers were well justified.
You are right though, these types of exams can easily end up becoming a game of "can I answer how the professor wants me to answer".
After my first stint in college I took about a decade off before returning for graduate school. I made it a policy to research all of my professors before classes began. If they had a book published, I bought it, and read it. It gave me remarkable insight into all of my professors (at least the ones who had published) before class actually began, and made it much easier to navigate the subjective grading minefield that so often exists.
That would be a valid concern regardless or your or professor’s race.
And even if we take into account that people are more biased towards opinions that elevate them, we should also take into account what an average college history teacher believes in. At that point you should probably be worried that your view isn’t Marxist enough.
Show me an economics program in the US pushing Marxist theory throughout.
Data on Marxist self-identification among professors, table 12: https://www.researchgate.net/publication/287093322_The_socia...
They'd probably also try to temper the enthusiastic incorrectness of freshman coming in as full-on 1930s-throwback "Stalin was awesome, actually" tankies, but there just aren't that many of those. The confidently-wrong freshmen tend to all fit a similar mold, and it's not leftist.