Republican Party from 1975 through 1979, and was the state co-chair of Ronald Reagan's 1976 presidential campaign. He was also an elected member of the Wisconsin Conservation Congress from 1975 to 1980. Wisconsin Circuit Court Wilcox ultimately returned to public office in 1979 at the behest of Governor Martin J. Schreiber. Schreiber had appointed James Poole to the Waushara Circuit Court judgeship in 1978 after the death of Judge Boyd A. Clark, but Poole died unexpectedly on the day he filed to run for a full term in 1979. An aide to Schreiber asked Wilcox to consider running for the seat. Wilcox eventually decided to pursue election as a write-in candidate and was victorious in the April 1979 election. He would go on to be re-elected without opposition in 1985 and 1991. Due to its small population, Wilcox was the only judge for Waushara County. He saw every state case in the county, for situations ranging from criminal prosecution to property or liability disputes. He served as chairman of the Wisconsin Sentencing Commission from 1987 to 1992. During his later years on the court, he also served as a faculty member of the Wisconsin Judicial College. Chief Judge In 1985, the Wisconsin Supreme Court appointed Wilcox Chief Judge of the 6th Administrative District of Wisconsin Circuit Courts, comprising, at the time, the counties of Adams, Clark, Columbia, Dodge, Green Lake, Juneau, Marquette, Portage, Sauk, Waushara, and Wood. As chief judge, he was empowered to assign judges, oversee the caseflow, and supervise the personnel and budget of the courts within his administrative district. Wilcox served three two-year terms as chief judge, which at the time was the statutory maximum for consecutive terms. He was elected chairman of the Wisconsin Chief Judges Committee in 1990. Wisconsin Supreme Court In May, 1992, Wisconsin Supreme Court Justice William G. Callow announced that he would resign, effective September 1. Wisconsin Governor Tommy Thompson selected Wilcox to fill the vacancy, and he was sworn in on October 7, 1992. The appointment would allow Wilcox to fill out the remainder of Callow's ten-year term, expiring in 1997. Wilcox decided to stand for election to a full ten-year term in 1997, and faced ACLU attorney Walter Kelly. Wilcox won the election by a large margin, but his victory spawned allegations of campaign finance violations which would develop into a John Doe investigation. 1997 election campaign controversy Wilcox was