At the University of Wisconsin, the precinct with most of the frats has traditionally been the most heavily Democratic precinct on campus.
This is interesting. Any guesses as to why?
Hard to say for sure, but I'd guess it has something to do with demographic differences between the students who join Greek life from the general student body. One of the common tropes about the UW student body is the division between Sconnies (ie students who are from Wisconsin) and Coasties (ie students from the coasts). There is a long list of stereotypes associated with each, but suffice to say being in a frat is a Coastie stereotype, and that we would expect Coasties to vote quite a bit to the left of Sconnies.
