Most leftists or Democrats I know seem to be very inclusive, including myself (I try at least), but some are very anti-Trump, claim to be inclusive and for equal rights, but they are very offensive, discriminating against, and cruel to/bullying the non-wealthy, disabled, gay/trans people, and more.
People are a spectrum in all spaces. You are a product of your environment. When a person is racist, or prejudice, it typically means they are inexperienced and have a fear of the unknown with a fight preference in their fight or flight mechanism.
If they had the life experiences to have encountered diverse people, they would have realized there is no difference at all. If they are intelligent enough they will learn from the experiences of others with logical empathy.
Racism is telling you, the person lacks curiosity. That in turn tells you that they have not explored much in life and likely do not read regularly. They are not a life long learner and have likely lost the majority of what they learned in school. This means they are functional in their life niche but stupid and have no character depth. They may appear normal on the surface, but in the game of life, they hold a terrible hand and will always disappoint. Anyone that shows such prejudice has no real ethics or values. They are showing you their poker hand and daring you to be dumb enough to include them in your game. For some people, politics are a brand and team sport.