A person who cares too much about what is and isn't politically correct.
Mark: Hey, Nick, look at this. This guy in the chat room is getting all bent out of shape because I called President Obama black instead of African-American.
Nick: Wow. This dude is the very definition of a PC Twinkie.
A person that becomes an admin/moderator of several online forums for the sole purpose of having the title. Power mods tend to contribute minimal to their communities and are only there for the benefits.
Mark: Hey, look at this guy's profile. He moderates 129 communities but has only posted 2 comments in the past week.
Nick: Yup, this guy is a total power mod. I'd be surprised if he gave even one fuck about the forums that he manage.