As stated, I don't think public conferences are an appropriate forum for this kind of polarized argument, but it's not wrong either. Wearing a MAGA hat is declaring your alignment with a political platform that pervasively equates mexicans with dirty criminals, muslims with terrorists, gay and trans people with the mentally ill, and anyone who isn't a white rural christian with "not a real american".
That's intolerance, straight up. And that's what you're telling me if you wear that thing. And if it's my environment your standing in I don't have to put up with it. Refusing to tolerate intolerance is the paradox, and the solution is to get out of my face with that hat.