In recent months, a group of self-proclaimed “constitutional sheriffs” in Washington state has announced that they will not enforce the state’s new gun law, which tightens background checks and bans people under 21 years old from buying semi-automatic weapons. Asserting that the Second Amendment prohibits laws involving “registration of personal firearms under any circumstances,” members of the constitutional sheriffs movement declare that they have the right, even the duty, to refuse to enforce gun laws. Their refusal raises a thorny question: Should government officials ever refuse to enforce laws they personally believe are invalid?

The constitutional sheriffs movement likes to portray itself as a new incarnation of the civil rights movement, which follows Martin Luther King’s belief in “a moral responsibility to disobey unjust laws.” But, as I have argued, the movement owes more to the Ku Klux Klan than to King’s philosophy of civil disobedience.

Richard Mack, founder of the Constitutional Sheriffs and Peace Officers Association and leading spokesman for the constitutional sheriffs movement, has frequently claimed that if sheriffs in the South had recognized their authority to disregard unconstitutional laws, they would not have arrested Rosa Parks when she refused to move to the back of the bus. In contrast with Mack’s fantasies, the reality of police abuses during the Jim Crow era reveals the dangers that arise when law enforcement officials disregard laws they believe are unconstitutional. Throughout the civil rights era, government officials across the South did assert authority not to follow unconstitutional laws. But the laws they considered invalid were not the state laws imposing segregation but instead were the federal laws and court orders that required states to dismantle segregation. In 1956, nearly every Southern member of Congress signed the Southern Manifesto, which described Brown v. Board as a “clear abuse of judicial power” and called on state governments to resist desegregation “by any lawful means.” In what has become known as “massive resistance,” state and local officials enthusiastically heeded that call. Eight states adopted interposition resolutions that proclaimed federal desegregation orders unconstitutional. Declaring, “Segregation now, segregation tomorrow, and segregation forever,” Alabama Gov. George Wallace stood in the schoolhouse door at the University of Alabama to personally block the enforcement of desegregation orders that he believed violated the rights of whites to choose segregation. In the face of Southern defiance, Presidents Eisenhower and Kennedy ordered federal troops to enforce desegregation orders and allow black students to attend previously all-white schools.

The constitutional sheriffs movement is, in fact, a direct descendent of the Ku Klux Klan. In the 1960s, the Klan criticized Southern police for not protecting the white population from what the Klan considered unconstitutional civil rights laws and federal court orders. In the following decade, Klan members formed the Posse Comitatus movement, which transformed this idea into national action. The Posse movement argued that not only were federal civil rights laws unconstitutional, but so were federal tax laws, environmental laws, and gun laws, to name a few. It proclaimed that the county sheriff is the only legitimate law enforcement agent and declared that the sheriff has a duty to prevent federal agents from enforcing oppressive laws. If sheriffs refused to do their duty, the group declared, the people should create citizen posses, or militias, to resist federal tyranny by force. The Posse movement’s founder stated, “The law is that your citizens—a posse—will hang an official who violated the law and the Constitution.” A wave of anti-government violence followed.

The constitutional sheriffs movement is, in fact, a direct descendent of the Ku Klux Klan.

Although the Posse Comitatus movement faded in the 1980s after several leaders were killed in police shootouts and others were imprisoned, the Posse philosophy has now been resurrected in the constitutional sheriffs movement. Mack himself has long espoused views literally straight out of the Posse handbook. In a 2009 interview, Mack said, “I pray for the day that a sheriff in this country will arrest an IRS agent.” He also has continued to spout the crypto–anti-Semitism favored by the Posse. “There is one person who I believe can stop this New World Order. His name is your county sheriff,” Mack told Alex Jones in 2009. “There is no question your sheriff has the responsibility to protect you from tyranny and international bankers.”

The chaos and violence threatened by the constitutional sheriffs movement, meanwhile, was on full display in the 2014 confrontation between the federal Bureau of Land Management and rancher Cliven Bundy. Bundy called for armed resistance to support his refusal to pay more than $1 million in overdue grazing fees, and Mack and several other constitutional sheriffs joined the mob of roughly 1,000 armed protesters. Expressing his idiosyncratic understanding of the civil rights movement, Mack called Bundy a new Rosa Parks.

As this history reveals, time and again the principle that law enforcement officers should refuse to enforce laws they consider unconstitutional has been advanced by those on the wrong side of constitutional history. That principle has frequently been advanced to support extremist constitutional views far outside the mainstream, such as the Posse’s view that federal agents have no authority to enforce tax laws, or Cliven Bundy’s view that the federal government lacks authority to own and maintain public lands.

But even if the idea weren’t being pushed by extremists, it would still be deeply troubling because ordinary political disagreements can easily be expressed as disagreements over the Constitution. Empowering sheriffs to refuse to enforce laws they deem unconstitutional gives them authority to disregard laws simply because they disagree with them.

Mack likes to say that the outcome of the Nuremberg tribunals justifies sheriffs’ refusal to enforce gun laws.

“The officers at Nuremberg said the same thing, ‘We were just following orders.’ Well the court determined that following orders when you’re committing a crime, or genocide, doesn’t cut it,” Mack told the Washington Post in 2016. “We say the same thing. Do not say, ‘I’m just following orders.’ Do what’s right.”

In reality, the Nuremberg tribunals established a much more limited principle than the proposition that government agents should disregard laws they don’t like and just “do what’s right.”

Indeed, under U.S. military law, which incorporates the Nuremberg principle, soldiers may only refuse orders that are clearly invalid: In the words of Army regulations, the duty applies only when “a person of ordinary sense and understanding would have known the orders to be unlawful.” Pursuant to that standard, soldiers can be prosecuted when they refuse to follow orders based on their own beliefs about what orders are invalid, as military courts ruled in court-martial proceedings. The United States Department of Justice in 1994 adopted a similar position on its authority to refuse to enforce or defend unconstitutional laws: It would exercise that authority only when a law’s unconstitutionality was clearly established. (Occasionally, the government has appeared to depart from that policy. Last year, for instance, the DOJ declined to defend in court key portions of the Affordable Care Act in a move the New York Times described as “highly unusual.”)

Stripped of its constitutional and patriotic rhetoric, the constitutional sheriffs movement should be seen for what it is: an extremist movement comprised of sheriffs willing to abuse their power as law enforcement agents to thwart even modest gun laws. Far from following the Constitution, the movement expresses contempt for the American constitutional system, which has long established a system of checks and balances that gives the people power through their elected officials to enact the laws they want, subject to review by courts that can determine whether laws comply with the Constitution. In this system, we can expect criminals to defy the laws, but we should all be concerned when the lawman goes rogue.