I think it is true across political lines and sides of the issues.

IMO, a big part of it is also driven by attempts to be inclusive in media and educational representation. You get your TV and movies with the obligatory black, gay, and trans characters. If media reflected real life demographics, most of these wouldnt exist. Blacks are 12% of the US population, gays are ~5%, and trans people are ~1% depending on the survey. When surveyed, people think they are closer to 40%, 25%, and 20% of the population because they are so often overrepresented.