Very common phrase at the University of Minnesota. Refers to anyone studying at the Carlson School of Management. On campus, Douchebag and Carlson are basically synonymous. It is presumed that every Carlson student is a douchebag, so the few who are not must be identified specifically as "not a douchebag" by someone in CLA to be accepted by anyone cool on campus.
CLA Girl: "Hey what's your major?"
Carlson Douchebag: "International Supplier Relations and Human Resources Management"
CLA Girl: "Oh... I have to go..."
CLA Girl: "I met a cute guy, but turns out he goes to Carlson"
CLA Guy: "Douchebag."