For example: claiming gay people are pedophiles, or that trans women are men in dresses trying to sneak into bathrooms to assault people.
Claims like this--and these are the tip of the iceberg--target groups of people and affect every individual within. It's like passive libel/slander that every member of the group has to contend with.
It can even affect people outside the group. I don't think I know of a straight man under 30 who isn't afraid someone will think they're gay if they do the wrong thing. And more than a few cisgender women get run out of bathrooms because they present in a more masculine way.
Publicly denouncing a group of specific folks as communists, when they were in fact not communists I believe was illegal even in the McCarthy era (that's libel if posted and slander if spoken publicly).