What if the jerky boss is the head of this organization (meaning there's no "higher-up" for him to complain to)?
Or, if there is and he does complain, the jerky boss might still make life difficult for him.
My hus' was fired after complaining about his manager to her boss--despite the fact that the other employees hated her equally and there had already been multiple complaints about her. (This was a crappy bookstore job, so he wasn't too sorry to leave. On the other hand, it kind of sucks that it's so difficult to get rid of a crappy boss.)
As long as this is an easily-obtained entry level position, the easiest thing is probably to get out of there before things really blow up.