If you use demographics, there aren't all that many NPR listeners out there compared to the more mainstream media listened to and watched by most of the world.
I have observed during my many years of trying to be normal, otherwise known as pretending to be a guy, once people feel safe about having to be PC that is when you find out what the really think; or at least say to go along with the herd perhaps?
When they hear transsexual, it essentially only applies to MtF, mostly a TV by their definition, some feaky guy in a dress (think Jerry Springer, et al), followed by a gorgeous drag queen or Lady-Boy that of course they "Could tell". Hell I had a hard time in Thailand playing is she or isn't she with our local sales guy! FtMs are just diesel dykes with penis envy. Besides, they are women and therefore do not really count to start with.
The shocking video of Chrissy Lee Polis getting the crap beat out of her and TIDOR serve as good reminders of how many "mainstream" people think of transsexuals. Only one little old lady out of all the people at McD's that were watching, stood up and did the right thing. We're the dogs that are OK to kick.