Retired Chief Justice Michael L. Bender joined more than 100 of his state and federal counterparts last week in arguing for the dismissal of criminal charges against a Wisconsin judge indicted for obstructing immigration authorities who were operating at her courthouse.

Milwaukee County Circuit Court Judge Hannah C. Dugan stands accused of knowingly concealing a man wanted by immigration officials and obstructing attempts to apprehend him. Dugan’s federal indictment alleges U.S. Immigration and Customs Enforcement agents had an administrative warrant for a misdemeanor defendant appearing in Dugan’s courtroom in April, but she directed the defendant to leave through a side door.

Last week, 138 retired state and federal judges, including Bender, submitted a brief in support of Dugan, arguing the prosecution of a judge for the way she manages her courtroom sets an alarming precedent for judicial independence and state sovereignty.

“Should this Court allow the prosecution of Judge Dugan to proceed, judges in every state and federal courthouse across the nation will feel a constant, ever-present threat to refrain from actions that might antagonize federal officials, and it will not just be limited to immigration enforcement. Let this case serve as a warning for what else could come should this prosecution be allowed to go forward,” wrote the group of judges in the May 30 filing.

Bender joined the Colorado Supreme Court in 1997 as an appointee of Gov. Roy Romer. He became chief justice in 2010 and served until he reached the mandatory retirement age in 2014. 

Also joining the brief was John P. Leopold, a former judge and chief judge of the previously configured 18th Judicial District in suburban Denver. Leopold was on the bench from 1987-2006.

Dugan has moved to dismiss her indictment in the Eastern District of Wisconsin on the grounds that she is entitled to judicial immunity for her alleged actions. Her motion cited Trump v. United States, the U.S. Supreme Court’s decision from 2024 granting then-candidate Donald Trump immunity from criminal prosecution for actions within his official authority he took in his first presidential term.

“Even if (contrary to what the trial evidence would show) Judge Dugan took the actions the complaint alleges, these plainly were judicial acts for which she has absolute immunity,” wrote Dugan’s attorneys. “Judges are empowered to maintain control over their courtrooms specifically and the courthouse generally.”

The retired judges’ brief echoed that argument, and contended it was also a “direct affront to state sovereignty” to permit federal immigration officers to operate in state courthouses and require judges to assist them.

“For instance, if the courtroom has two exits, a judge might conclude that they must first inquire of another branch about which exit a party must use to enter or leave the courtroom,” the judges wrote. Such an approach would “prioritize the interest of federal officers, whenever they appear, over the parties, witnesses, and victims in the case and above the requirements of the state law.”

The government has not yet responded to Dugan’s motion to dismiss.