Zoe,

Here are my possible, personal definitions of "hoi-poloi":

--Groups of people whose opinions and taste don't matter to me.  Needless to say there are many such groups in my life. But then again the "hoi-poloi" might call people like me "hoity-toity", which only proves that everyone has an appropriately condescending name for everyone else.
--People who prefer sheer entertainment as opposed to literary theater.
--People who are symbolized by the zombies in The Walking Dead, which could very well be a series about people avoiding being chased and consumed by other people who are unlike them.