Most people believe what they believe (negative) for a reason -- usually ignorance or negative influences, but maybe hurt. Especially for ignorance, it is easy to pick on other groups when your echo chamber doesn't contain people from those groups. But when someone from that other group materializes to you, becomes a living person who you have to deal with, that's when the real decision is made. Now realizing I boiled a whole person down to one aspect of their life, am I going to become a toxic person and cling to dehumanizing you into a single aspect? Or am I going to grow past it?
To your question. If it were me, I would ignore them and not get involved in their personal life. Keep it professional. If their bias is against you and you are stuck interacting with them in person, the most impactful thing you can do is expose your humanness. They see you love your kids just as much as they love their kids. Or you like that same show that they like. Or whatever. Seeing you as human strikes at the core of such beliefs. I think most people are not a bad sort and can grow past it. But a rare few will intensify the toxicity because growing is too hard for them (maybe brain chemistry or belief is co-mingled with identity so changing it is like dying). It is not worth being around a persistently toxic person. Transfer or change jobs if necessary.
I also think it is a trap to believe yourself better than such a person mentioned in your post. You might be in some ways, but we each have our own biases and preconceived notions. It's one of the ways our brain deals with vastly different cultures which we don't understand. We lack enough information, so we substitute with quick generalizations (often from other people in our social sphere). But when we have better information, our simplistic model can be replaced with the richer one. It can be a tough process, especially so for some.