By Jason Stein

Wisconsin Supreme Court Justice David Prosser announced Wednesday that he's retiring on July 31 after nearly 18 years on the high court -- including some of its most turbulent -- and four decades in public life.

The retirement hands GOP Gov. Scott Walker a second opportunity to appoint a new justice and put his imprint on the state's highest court with a jurist who could then stand for election in 2020. Prosser was a member of the court's conservative 5-2 majority and so Walker's appointment wouldn't necessarily change that dynamic.

Prosser, 73, leaves behind a court where controversy has become as common for justices as it is for other elected officials in Wisconsin. His clashes with the court's liberal justices extended to charged language and, in 2011, a physical altercation.

"It has been a tremendous honor to serve the people of Wisconsin in various capacities for more than 40 years. During this time, I have had the exceptional privilege of working in all three branches of state government, including 18 years as a representative in the state Assembly and 18 years as a justice on the Wisconsin Supreme Court," Prosser wrote in a letter to Walker Wednesday.

Walker's office had no immediate comment and Prosser did not return a phone call about his retirement, which had been rumored for months.

In an interview in March, Prosser said he wasn't sure if he would fill out his full term, which runs until 2021.

Asked then if he would retire this summer, he said, "That remains to be seen." He emphasized he had not made up his mind and said he would like to serve at least until the summer of 2017.

Prosser's successor will get to serve until the first spring without a Supreme Court election already scheduled, or 2020, and if elected then would serve a full 10 year term.

In his career, Prosser took on nearly every aspect of writing, enforcing and interpreting the laws of Wisconsin and the country.

As a young Republican official, he worked in the office of then-U.S. Rep. Harold V. Froehlich, as an attorney for the U.S. Department of Justice, and as the Outagamie County district attorney.

From 1978 through 1996, Prosser served in the state Assembly, including two years as speaker and five years as minority leader. He sat on the Wisconsin Tax Appeals Commission and in 1998 was appointed by then GOP Gov. Tommy Thompson to the Supreme Court.

Prosser served on the court during the rough recent years in which court elections, and even private deliberations of the panel, grew sharply partisan.

In 2011, Prosser defeated liberal challenger JoAnne Kloppenburg by 0.5% of the vote in an election that led to a rare statewide recount.

The race took an unexpected twist after Walker unveiled the law now know as Act 10, which curbed collective bargaining for most public employees. Unions rallied behind Kloppenburg in the hope that she would vote to overturn the law in ultimately unsuccessful court challenges, while conservatives defended both Prosser and the legislation.

Prosser ended up backing the law later that year in a charged lawsuit that led to a physical altercation between Prosser and another justice while they and other members of the court argued privately about when and how to announce their decision reinstating Act 10.

During the argument, Justice Ann Walsh Bradley approached Prosser to order him to leave her office and, in that confrontation, Prosser's hands ended up around Bradley's neck. The court's liberal and conservative justices disagreed in their retelling of the incident about which of the two justices had acted aggressively.

Prosser defended his action as a reflexive response to a perceived threat but acknowledged later to a detective "feeling the warmth on the side of Justice Bradley's neck." Bradley said she had not been physically hurt but had been caused unwarranted distress.

In another official interview after the fact, conservative Supreme Court Justice Annette K. Ziegler succinctly summed up the fracas.

"The whole thing was just bizarre," Ziegler said.

The state Judicial Commission filed ethics charges against Prosser, but the case stalled when most of the justices said they could not participate in the case because they had witnessed the incident. In Wisconsin, the high court alone decides judicial ethics cases, even for its own members.

At the time of the commission's complaint, Prosser dismissed it as a politically motivated attack that sought "to accomplish through this prosecution what some of its members failed to achieve at the ballot box."

In a separate incident in February 2010, Prosser also called then Chief Justice Shirley Abrahamson a "total bitch" and threatened to "destroy" her.

In a statement Wednesday, Supreme Court Chief Justice Patience Drake Roggensack praised Prosser.

"Justice David T. Prosser is an exceptionally bright and thoughtful jurist whose presence on the court will be greatly missed. David has brought unique perspectives to court discussions, thereby increasing the court's ability to understand difficult problems presented to us for resolution," Roggensack said.

Attention will now shift to Walker and who he will put on the court.

"In choosing my successor, Governor, I respectfully request that you select a person who is fully committed to the important mission of the judiciary," Prosser wrote in his retirement letter. "Such a person will understand that promoting the reputation and integrity of the institution is more important than the promotion of any individual."

(c)2016 the Milwaukee Journal Sentinel