Definitely terrifying and can be surprising, but I think it's easier to demonize unfamiliar groups than to demonize a well-known one. I think demonizing and dehumanizing relies on some degree of the unknown to make all the hysteria and fear plausible. If the group is well known by the general public, it's easier to say "now wait a minute, I happen to know many trans people and they're very kind." It creates a strong base of informed allies to speak up on the group's behalf. It's not impossible to demonize a well-known group, I just believe it's easier when your target has no personal interactions to check against the fear mongering.