Coleman attended the University of Minnesota as both an undergraduate and law student. He then worked for eight years in Hennepin County as a public defender and prosecutor. Proposals to build a metal shredder along the Mississippi River in Saint Paul inspired his first run for the Saint Paul City Council. Coleman represented Saint Paul's Ward 2 from 1997 to 2003. While on the city council he was also an investment management consultant specializing in nonprofit organizations and endowments for RBC Dain Rauscher. He was also president of United Family Practice Medical Center.