After graduating, he served as a law clerk at the district court level in Minnesota and the circuit court level in Wisconsin. He became the half-time Assistant District Attorney in Langlade County and worked the other half time at a private law office while also serving as Deputy Corporation Counsel for Forest County. Gableman then worked as an assistant district attorney in Marathon County. He served as District Attorney of Ashland County from 1999-2002. In 2002, he was appointed the circuit court judge for Burnett County, and then elected Circuit Court Judge for Burnett County in 2003, with 78% of the vote. In Burnett County, Gableman established an inmate community service program, a juvenile community service program, a drug and alcohol court, and a restorative justice program for which he served as chairman of the board for six years. He also was an adjunct professor of law at Hamline University School of Law, teaching criminal procedure and professional responsibility. On April 1, 2008, Gableman defeated Louis Butler for a seat on the Wisconsin Supreme Court 51% to 49%, making him the first candidate since 1967 to defeat an incumbent justice. In 2009 the Wisconsin Judicial Commission brought an ethics charge against Gableman. The charge alleged that a campaign advertisement in which he accused Butler of working "to put criminals on the street" and accusing Butler of finding a "loophole" that resulted in the release of a child molester, was false and misleading. Gableman claimed in his defense that his free speech rights are violated by the judicial conduct rule he is accused of breaking. A three-judge panel was charged with the preliminary investigation into whether the campaign ad violated the Wisconsin Code of Judicial Conduct. In November 2009, the panel unanimously recommended that the complaint against Gableman be dismissed. Procedure required that the Wisconsin Supreme Court make the final determination as to whether there was an ethics violation. When the court deadlocked 3-3, the commission stopped pursuing the case. In January 2011, the group 9to5 Milwaukee filed an ethics complaint with the Wisconsin Government Accountability Board against Gableman for failing to recuse himself from a case in which he had allegedly had a financial interest. The justice received legal counsel from July 2008 to July 2010 from the Wisconsin law firm of Michael Best & Friedrich on a contingency fee basis. Gableman received the services from the law firm as it defended him against a separate ethics charge. Gableman never declared the receipt of the services in official disclosure statements. Critics characterized the legal contingency-fee arrangement as "free" legal services, a characterization the law firm rejected. In 2016, Gableman described himself as a judicial conservative. In 2017, Gableman said he would not run for re-election in 2018.
