Washington (CNN) A federal judge in Wisconsin has penned a caustic essay accusing Chief Justice John Roberts of "undermining democracy" and placing him at the center of problems in a polarized America, just as Roberts has been increasingly trying to defend the Court from US politics.

In a piece ricocheting across social media and provoking conservatives, US District Court Judge Lynn Adelman, a 1997 appointee of former President Bill Clinton, writes that Roberts' confirmation pledge to be an umpire merely calling balls and strikes "was a masterpiece of disingenuousness."

"The Roberts Court has been anything but passive," Adelman says in his 35-page essay . "Rather, the Court's hard right majority is actively participating in undermining American democracy."

Adelman highlights decisions such as the 2013 Shelby County v. Holder decision that curtailed the reach of the 1965 Voting Rights Act and the 2010 Citizens United v. Federal Election Commission ruling that lifted campaign finance regulations. Both cases were decided by 5-4 votes, with Republican-appointed conservatives holding the majority.

An overriding point of Adelman, a former Wisconsin state senator known for his liberalism, is that the high court answers the desires of wealthy people while shortchanging ordinary Americans.

Such criticism from a fellow federal judge is startling, although Adelman's key points have long been detailed by liberal advocates, law professors and other writers. Rarely do jurists break ranks so publicly and personally.

He described Roberts' 2005 Senate confirmation testimony as "misleading" and declared that "the Roberts Court has contributed to insuring that the political system in the United States pays little attention to ordinary Americans and responds only to the wishes of a relatively small number of powerful corporations and individuals."

In a telephone interview with CNN on Thursday, Adelman said he has been caught off guard by attention to his law review essay.

"All this fuss has disarmed me," he said, but quickly added, "I felt it needed to be said. Other people have written on this subject. But it's such an important issue. You can't say it enough." He said he wanted to add his unique perspective as a judge.

In his essay, he wrote, "We desperately need public officials who will work to revitalize our democratic republic. Unfortunately, the conservative Justices on the Roberts Court are not among them."

The piece, entitled "The Roberts Court's Assault on Democracy," will be in the Harvard Law & Policy Review, a student law journal published by the liberal American Constitution Society.

Adelman's assessment has burst forth amid Roberts' recent efforts to rope off the Court and just a week after scorching exchanges at the fulcrum of the law and politics. Roberts issued a rare statement to defend conservative justices against attacks by Senate Democratic Leader Chuck Schumer during an abortion-rights case, and President Donald Trump separately lashed out on Twitter against liberal justices Sonia Sotomayor and Ruth Bader Ginsburg.

Roberts did not respond to a request for comment.

Adelman, who is 80 and still hearing cases in Milwaukee, has spawned a heated round of critiques, from conservatives, who have denounced him, and liberals, praising his candor.

"This screed could have come from a Bernie stump speech," Professor Josh Blackman wrote on the right-leaning Volokh Conspiracy legal blog. "It has no place in a publication by a federal judge. ... There is nothing new or original here. Judge Adelman merely repeats the same tropes we have heard for a decade."

Blackman, a professor at the South Texas College of Law in Houston, also suggested Adelman compromised judicial ethics by publishing his complaints, which included a biting critique of Trump, and then by talking to reporters.

U.S. District Judge Lynn Adelman

From the opposite perspective, Slate commentators Dahlia Lithwick and Mark Joseph Stern acknowledged in a piece on Tuesday that in the past the judge might have been challenging the usual norms in his scathing essay.

But they wrote, "It is in the finest tradition of the judicial branch to sacrifice decorum and politeness to calls for actual justice, especially when the rights of minorities, women, the poor, and the disenfranchised have been hollowed out by monied interests and the political branches that answer to them.

"The real tragedy here," Lithwick and Stern added, "is that progressive judges will be pilloried for saying out loud what conservative judges have secretly, and not so secretly, crowed about themselves for decades."

Adelman told CNN he believes he crossed no line and, rather, fulfilled a duty.

"It's reasonable to criticize decisions of the Supreme Court," he said. "I understand that I'm bound by them. And I've done that (in rulings). But I think I have a duty to criticize decisions that are flawed."