MADISON, Wis. (Legal Newsline) - Wisconsin Supreme Court Justice David Prosser is claiming he can be "completely impartial" in a case regarding a controversial campaign advertising rule.

Prosser, in a letter to the parties involved in the case Thursday, disclosed the facts involving his situation.

In it, he says he has "no bias or prejudice against any party or party's attorney in this case and a favorable view of multiple attorneys on different sides of the case."

The main sticking point: Attorney James R. Troupis is arguing the case on behalf of conservative groups that feel the administrative rule, known as GAB 1.28, violates their constitutional rights to free speech.

Troupis, Prosser admits in his letter, served as lead counsel for his campaign committee during the recount that followed the state Supreme Court election in April.

According to the recount results, Prosser received 752,323 votes to Wisconsin Assistant Attorney General JoAnne Kloppenburg's 745,007. Kloppenburg conceded defeat a couple of months later.

"Attorney Troupis has been a friend for two decades and is widely recognized as an expert in election law, so it is not surprising that my committee turned to him last April," Prosser wrote.

Prosser also wrote that Assistant Attorney General Clayton Kawski, who represents the members of the Wisconsin Government Accountability Board and its executive director, Kevin Kennedy, is "a close friend who served as my sole law clerk during the Supreme Court's 2007-2008 term and provided public support in my recent campaign."

Moreover, Prosser -- who is still under investigation for allegedly attacking a fellow justice -- says he knows all of the named defendants personally.

"I appeared before Circuit Judge Gordon Myse and Circuit Judge Thomas Cane when I was Outagamie County District Attorney. I supported and contributed to Judge Myse when he ran for the Supreme Court in 1983, and worked hard to persuade Gov. Lee Sherman Dreyfus to appoint Judge Cane to the Court of Appeals.

"I have known Judge (Thomas) Barland for many years and attended his retirement celebration. I also attended the retirement celebration of Judge Michael Brennan in Neillsville. I have been in the homes of Judge (Gerald C.) Nichol and Judge (David G.) Deininger and was a close friend of Judge Deininger in the Legislature. I have known and worked with Kevin Kennedy for at least 30 years.

"In addition, Attorney Robert H. Friebert of Friebert, Finerty & St. John, S.C., who represents the Wisconsin Education Association Council and Mary Bell, endorsed me in my recent campaign," the justice wrote.

Prosser, in making his case to participate, maintains he doesn't have "a favorite 'horse in this race.'"

Last July, the GAB, which is charged with oversight of the state's campaign finance, elections, ethics and lobbying laws, issued a new administrative rule regarding campaign advertisements.

The rule, the GAB explained, uses a common-sense test in determining whether an ad has a political purpose and is subject to statutory disclosure and disclaimer requirements.

An ad is considered to have a political purpose if it is "susceptible of no reasonable interpretation other than as an appeal to vote for or against a specific candidate."

If an ad meets these and other specific criteria, it is then subject to the applicable campaign finance regulations and requirements in Chapter 11 of Wisconsin Statutes.

Previously, a campaign ad had to expressly advocate the election, defeat, recall or retention of a clearly identified candidate. Express advocacy was defined by the use of certain "magic words" or their functional equivalents for it to be subject to campaign finance laws requiring disclosure of who paid for the ad.

However, those rules led to numerous campaign ads by independent groups that skirted regulation by avoiding the use of certain words, such as "vote for" and "vote against."

"This rule means that if people or groups run independent ads, which for all intents and purposes are political ads for or against a candidate, they will be required to disclose what they're doing and where the money is coming from," Kennedy said at the time. "It will improve transparency in campaign finance and elections, and help voters make informed decisions at the ballot box."

But several groups challenged the rule in two federal lawsuits. Other organizations and individuals, including Wisconsin Prosperity Inc., filed a challenge in the state Supreme Court. They argued the rule violated the First Amendment.

The federal lawsuits were stayed pending a ruling by the state's high court. Last August, the Court granted a temporary injunction barring enforcement of the rule to "preserve the status quo."

The Court has scheduled oral arguments in the case for Sept. 6.

The Brennan Center for Justice at New York University School of Law, a nonpartisan public policy and law institute that focuses on the fundamental issues of democracy and justice, filed an amicus brief in support of the GAB.

The center argues that GAB 1.28 is "plainly constitutional."

It points to the "severe harm" to the public's and Wisconsin's interests that will occur if political spenders are permitted to "cloak their influence in secrecy."

"When money is spent to influence the outcome of elections, vigilance is required to ensure that influence peddling does not corrupt our democracy," the center wrote in its 19-page brief.

From Legal Newsline: Reach Jessica Karmasek by email at jessica@legalnewsline.com.