For a very long time, I’ve had mixed feelings about The Adventures of Tom Sawyer, specifically the character of Injun Joe. On one hand, Mark Twain harbored bizarrely intense animosity towards Amerindian people, and he uses Joe’s existence in the novel as an opportunity to pontificate on various racist ideas. On the other hand, Joe is a great villain. He’s intelligent, he’s ruthless in the pursuit of his objectives, and he has a well-developed backstory and plausible motivation. In some ways, he is even an inadvertent social commentary, as Joe identifies his motivation as a desire to fight back against the bigotry that has made his life miserable.
The reason I like Joe as a villain (minus Twain’s editorializing) is that I’m a big proponent of the idea that villains as well as heroes should have equal-opportunity hiring. Real life Awful People come in a rainbow of skin colors, ethnicities, religions, nationalities, disabilities, sexual orientations, and unpleasant personality traits. There is sometimes, among well-intentioned liberal types, a hesitation to write members of a marginalized group as less than saintly, much less a full-on jerk. This can quickly become problematic if the implication is that the group in question does not experience the full range of human emotion or personality traits. So I fully support writing diverse villains!
The interaction between a villain’s status membership in a marginalized group and their villainy requires more finesse to navigate. In some cases, it might not be relevant. If you’re writing a YA novel set in a Deaf school, the class bully’s deafness does not set her apart, and she can harass the protagonist without necessitating any further exploration of her Deaf identity. And even in circumstances where the character is a minority, there need not be any relationship between their identity and their bad behavior– if you have a trans male investment banker who acts like an selfish, combative jerk, there doesn’t need to be any delving into the interaction between his trans-ness and his inability to play nicely with others. The reader knows he chose to enter an industry known to attract the pathologically macho, and going out of your way to tie this back to his gender when it’s most likely just his personality has a lot of potential to go wrong.
Then again, the villain’s identity may have an interaction with their villainy, or even play a strong role in their route to the dark side*. A common trope is a villain who seeks to right a serious injustice visited upon them and/or their marginalized group, and goes too far to the other extreme. It’s common, in my opinion, because it works. Somewhat more subtly, the villain may have been pushed by their marginalized status into a situation where going bad is the only (or most accessible) route to success. Again, this is a potentially laudable urge– to beat a deeply unfair system– but the methods are what make the villain wrong.
*Obviously, there is a need for a high degree of self-awareness. Written sloppily, the marginalized villain can become an offensive stereotype, or worse, an airing of the author’s personal prejudices.