Last week, Michigan voters passed Proposal 1 making recreational use of marijuana legal, but students on campuses across Michigan shouldn't expect to see any changes to university policies banning marijuana.

Yesterday, Michigan State University said that students using marijuana on campus will face "legal and disciplinary" action. Freep.com reports that the University of Michigan, Central Michigan University and Wayne State University have all adopted similar policies.

Why?

A look at Grand Valley State University's drug policy before the passage of Proposal 1 gives a big clue. It says, "Consistent with federal law and the Drug Free Schools Act, GVSU prohibits the illegal use of any controlled substance. GVSU does not allow students to possess marijuana under any circumstance, regardless of medicinal status in the state of Michigan."

The Drug Free Schools and Communities Act has "several requirements with which all Institutions of Higher Education receiving any form of federal funding must comply." One of those requirements is to keep federally illegal drugs off of campus and out of university functions.

The threat of losing federal funding may not be the only reason Michigan's universities are banning marijuana, but you can be sure it's a deal breaker.