“We are not aware of a single case in our nation’s history where the president pardoned an elected official for disobeying a court order to stop violating constitutional rights,” said Ron Fein, legal director at Free Speech for People, which this week filed a friend-of-the-court brief challenging the pardon. “With this pardon, Trump has pushed our country into uncharted territory.”

Or so goes the argument by civil rights groups that say, for this reason, that President Donald Trump’s controversial pardon of former Sheriff Joe Arpaio cannot stand.

But what the founders could not possibly have envisioned was that a president would pardon an elected official for ignoring a court order to stop violating constitutional protections enshrined in the Bill of Rights. Those rights, after all, did not exist until two years after the Constitution came into force.

When the Founding Fathers created the presidential pardon power, they likely had a few ideas about how that authority could be used. Clemency might be granted in a show of mercy, or to undo a miscarriage of justice. Or maybe the president would want to pardon anti-government rebels in an attempt to restore peace to the republic, much like President Andrew Johnson would do after the Civil War.

Trump last month pardoned Arpaio, the former sheriff of Arizona’s Maricopa County, for a contempt conviction that stemmed from a 2011 racial-profiling lawsuit. In 2013, a federal judge ordered Arpaio to stop his office’s practice of unfairly singling out Latino drivers for special scrutiny in violation of the Fifth Amendment. But Arpaio’s deputies continued to racially profile Latinos, and in July, U.S. District Judge Susan Bolton found Arpaio in criminal contempt of court, ruling that he had “willfully violated” the order. He faces up to six months in jail.

Immediately following the pardon, Arpaio asked Bolton to vacate his conviction. Instead, she canceled his October sentencing hearing and ordered the former sheriff and the Department of Justice, which is prosecuting the case, to submit briefs on why she should or should not grant Arpaio’s request.

The Justice Department on Monday said it agrees with the pardon and urged the court to vacate the conviction. On the same day, two groups separately filed briefs opposing Arpaio’s request to dismiss his conviction, arguing that Trump’s pardon undermines judicial protections of constitutional rights.

The pardon sets a dangerous precedent, said David Shapiro, a lawyer at the Roderick and Solange MacArthur Justice Center, which filed an amicus brief arguing that the president cannot issue pardons that undo the judicial power to enforce the Bill of Rights. “I think the brief sort of sets forth that the concern is that [the pardon] sends a message to law enforcement that you can flout the Constitution and do it with impunity,” Shapiro said.

Law enforcement officials across the country now understand “that if they get into trouble and if the court orders them to stop doing something unconstitutional, they can disobey that court order and the president will issue them a get out of jail free card,” Fein said. “Most law enforcement officials won’t do that. Most will be scrupulous and follow court orders, but those like Joe Arpaio heard a very strong message from the pardon.”

The pardon power is not absolute. While the facts of Arpaio’s case are somewhat unique — both because of the underlying constitutional issues and because he has not yet been sentenced — challengers have been objecting to presidential pardons for centuries. But Fein said his group found only one other case where a presidential pardon infringed upon the Bill of Rights. In a 1915 case called Burdick v. United States, the Supreme Court protected the Fifth Amendment right against self-incrimination by holding that a newspaper editor’s refusal of a pardon, designed to compel him to reveal a source, voided the pardon.

The Supreme Court has also dealt with pardons related to criminal contempt on at least one occasion. In 1920, a court ordered a man named Phillip Grossman to stop operating a speakeasy in violation of prohibition. He continued to sell alcoholic drinks and was ultimately convicted of criminal contempt of court and sentenced to prison time and a $1,000 fine. President Calvin Coolidge issued a pardon that reduced Grossman’s sentence to the payment of the fine, and the pardon was challenged. The Supreme Court ultimately held that the president had the authority to pardon someone for a criminal contempt of court conviction. The critical difference between Grossman and Arpaio, the challengers say, is that there were no constitutional protections related to the order that Grossman denied. And that makes all the difference.

But even if the court decides that Arpaio’s pardon is valid, it should nonetheless deny Arpaio’s request to vacate the conviction, the MacArthur Justice Center lawyers argued. “The president has pardoned Arpaio in a manner repugnant to our constitutional order, rewarding him for waging war on minority communities and for breaking the law repeatedly and willfully,” they wrote in their brief. “The least this disgraced lawman should suffer is the stigma of conviction. The nation deserves for his conviction to stand.”

Trump’s pardon also raised questions about the potential impact on the Trump-Russia probe. “This pardon also sends a signal to people in Trump’s circle who may be implicated in the Russia scandal that if they get a court order to testify and they refuse, Trump is willing to bail them out of any criminal contempt of court through a pardon,” Fein said.

Arpaio gained national notoriety for his aggressive anti-immigration views and public humiliation of prisoners. America’s self-styled “toughest sheriff” operated Tent City, an outdoor jail where inmates in striped jumpsuits and pink underwear slept in tents that he once referred to as a “concentration camp.” Arpaio’s 24-year run as sheriff ended last year when he lost his bid for re-election. The court will hear arguments on Arpaio’s request to dismiss his conviction on October 4.