He was a justice of the Wisconsin Supreme Court for 15 years, appointed by Governor Tommy G. Thompson in 1992 and leaving office in 2007.
After obtaining his bachelor's degree in 1958, he joined the United States Army and was commissioned as an officer in a military police company.
[3] Wilcox began in private law practice at the La Crosse, Wisconsin, firm of Steele, Smyth, Klos & Flynn.
He soundly defeated Republican primary opponents Scott P. Anger and Clifford D. Bvocik, then went on to win the general election without opposition.
He served as Chairman of the Waushara County Republican Party from 1975 through 1979, and was the state co-chair of Ronald Reagan's 1976 presidential campaign.
[5] 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.
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.
Wilcox was involved in a controversy in 2001 when his 1997 re-election campaign was accused of an illegally coordinated get-out-the-vote effort with the group Wisconsin Coalition for Voter Participation.
[8] Although he denied knowing about the illegal coordination, Wilcox agreed to pay his $10,000 fine, and acknowledged that he bore the ultimate responsibility for the actions of his campaign staff.
The coalition's co-founder, former Assembly Republican staffer Brent Pickens, paid a $35,000 fine and promised not to work on any campaigns for the next five years.
[11] His term expired on July 31, 2007, and he was succeeded by Washington County Circuit Court Judge Annette K. Ziegler, who had defeated Madison attorney Linda Clifford in the April 2007 statewide election.
After leaving the Supreme Court, Wilcox would continue to serve as a reserve judge, and would occasionally hear cases.
In the Fall of 2023, with a new liberal majority on the Wisconsin Supreme Court and pending litigation that threatened to overturn the Republican legislative maps, Wisconsin Assembly speaker Robin Vos began threatening to impeach the newest justice, Janet Protasiewicz.