In January, more than 50 retired judges sent a letter to the court asking it to write new rules for when judges should excuse themselves from a case.

The state's highest court planned to consider the letter Thursday, but has rescheduled it for April 20. It is now on the open rules petition conference agenda, and the court will decide how to proceed from there, said Tom Sheehan, the court's spokesman.

The Wisconsin Institute for Law & Liberty, a conservative legal advocacy group, asked for the delay. It asked the court to allow a public hearing on the issue, according to a letter sent to the court Tuesday, two days before the court was set to review the request for the rule change.

"We intend to show the court that, given the court's action on this same issue in 2010 and the constitutional issues involved, the petition should be dismissed without a further and wasteful investment of judicial and public resources. We request that the court take this matter off its March 16 calendar. We will submit our opposition within the next 30 days," wrote Brian McGrath, legal counsel for the group.

The judges who wrote the letter want the state's highest court to establish a new standard for determining whether a judge should be disqualified from a case after she or he has received a campaign contribution or other help from a group or attorney. They are also asking for an amendment to the state Constitution allowing the court to appoint a state Court of Appeals judge to serve in place of a Supreme Court judge who has been dismissed, according to the petition.

One Wisconsin Now, a liberal advocacy group, said the delay further shows why recusal rules are needed in the state.

"The coalition of retired judges asking for this rule change were concerned about corruption or the appearance of corruption on the court. That the court would go along with this request from a conservative group is further proof the rules need to change to insulate the justices from influence of special interests,"said Jenni Dye, research director for One Wisconsin Now. 

The court last updated its recusal rules in 2010. The rules do not require recusal based solely on campaign contributions. Those who see the need for a change argue Wisconsin's laws contradict what the U.S. Supreme Court has prescribed for recusal. They point to a 2009 case, Caperton v. Massey, in which the justices agreed a large campaign contribution to a judge from a coal executive just before his case came before a West Virginia court was grounds for recusal by the judge. 

Those who oppose any changes to the state's recusal rules argue that the circumstances of the Massey case were distinct and do not pertain to Wisconsin. They also argue that additional restrictions based on campaign donations infringes on free speech protections. 

Since the petition was sent to the court in January, several legal advocacy groups have submitted comments.

Two national legal advocacy groups sent letters to the court endorsing the recusal petition. The Brennan Center for Justice, a liberal-leaning legal advocacy group based in New York City, and the Campaign Legal Center, a nonpartisan advocacy group based in Washington, D.C., support the creation of new rules and pointed to increased campaign spending in Wisconsin judicial races. 

Clear recusal rules would strengthen public confidence in Wisconsin's courts, Kate Barry, legal counsel for the Brennan Center, argued in a letter. 

"Wisconsin's current recusal rules creates the potential for conflicts of interest that could undermine public faith in the impartiality of the judiciary," she wrote.