About
Mac Blessen is the Lead OWI Attorney at Nelson Defense Group in Hudson, Wisconsin. He represents clients across western Wisconsin in criminal defense matters ranging from misdemeanors to serious felonies. His current practice areas include OWI/DUI, Drug Crimes, Gun Crimes, and Violent Crimes. He focuses on listening to clients, explaining the legal process clearly, and working toward resolutions that protect important interests such as a client’s license, job, and future.
Blessen attended Hamilton College and the University of Wisconsin Law School. During law school, he interned with Federal Defender Services of Wisconsin and the Wisconsin State Public Defender. His educational background included internships in federal and state public defense offices. Those law-school placements gave him direct exposure to defense work before he later served as a public defender in Baraboo, Wisconsin.
Blessen previously served as a public defender in Baraboo, Wisconsin, where he managed a high-volume caseload involving civil commitments, juvenile delinquency matters, misdemeanors, and felonies. Before entering legal practice, he worked in nonprofit communications in Washington, D.C., where he developed storytelling and advocacy skills. He brings that communication background to criminal defense and emphasizes presenting clients’ circumstances clearly while making sure they feel heard, informed, and supported throughout the legal process.
Mac Blessen uses a client-centered approach that emphasizes each client’s humanity and individual circumstances. His practice focuses heavily on OWI/DUI defense and extends to Drug Crimes, Gun Crimes, and Violent Crimes throughout western Wisconsin. He is a general member of the National College for DUI Defense. His work emphasizes clear communication, personalized attention, and defense advocacy centered on understanding the person behind the criminal charge.
Law Office Affiliations
- Attorney, Nelson Defense Group
- Member, State Bar of Wisconsin
Licensed State
- Wisconsin
Education
- University of Wisconsin Law School
Juris Doctor (J.D.)
Awards & Badges

- Civil Rights
- Criminal Defense
- Drug Crime
- DUI & DWI
- Violent Crime






