volunteurocrat
An organizer who repeatedly dominates position of responsibility and decision making by sheer virtue of having the capacity and resources to volunteer. This should not be confused with rank and file control, which requires broad rank and file participation.
A quarter of the branch is volunteurocrats keeping everything running, and the other three quarters keep quitting in two months because they don't plug into the work, so they have to keep getting easy recruits from campus. The cream of the volunteurocracy gets skimmed off into the nonprofit staff pool every election cycle.