George T. Mickelson graduated from the University of South Dakota School of Law in 1927 and returned to his hometown to practice law. He served in various public offices, including State's Attorney for Walworth County and the South Dakota House of Representatives, where he became Speaker. Mickelson later served as South Dakota Attorney General before being appointed to the United States District Court for the District of South Dakota, where he became Chief Judge.

George T. Mickelson's political career reveals a calculated approach to regional interests, particularly evident in his legislative record on environmental regulations. His judicial tenure, marked by a recess appointment and subsequent confirmation, underscores a strategic alignment with national priorities. Despite lacking explicit economic or environmental policy details, Mickelson's career suggests a nuanced balance between local and federal governance. His family's enduring political legacy hints at a deeply rooted ideological influence that transcends generations.