Although a federal district judge last week dismissed the criminal case against former Sheriff Joe Arpaio, who was pardoned by President Donald Trump, lawyers who challenged the constitutionality of the pardon say the fight is far from over.

“I don’t think that the decision by the judge in the criminal case is the end of the story,” said Ron Fein, legal director at Free Speech for People, one of the groups challenging the constitutionality of the pardon. “There is a viable challenge that could be launched, and we are actively exploring this on the same grounds that we mentioned in our friend of the court brief and be able to expand on it.”

As The Intercept previously reported, Free Speech for People is one of a number of groups that filed friend-of-the-court briefs in Arpaio’s criminal case to argue that Trump’s pardon was unconstitutional. The basis of their objection was that the pardon power is not absolute, and it does not allow the president to pardon an elected official for ignoring a court order to stop violating people’s constitutional rights, as the former Maricopa County, Arizona, sheriff did.

Now, Fein told The Intercept, the group is considering civil litigation on behalf of people whose rights were threatened as a result of Arpaio’s violation of the court order. Wanting to protect his legal strategy, Fein declined to share much about what the suit would entail.

“I think the basic argument is that the pardon violates the due process rights clause and constitutional guarantee of equal protection of the laws, and I don’t want to expand further on that,” Fein said.

Trump in August pardoned Arpaio for his July conviction for criminal contempt of court for what U.S. District Judge Susan Bolton called a “flagrant disregard” of a court order to stop his office’s unconstitutional practice of racial profiling. Bolton upheld Trump’s controversial pardon last week, dismissing the criminal contempt case with prejudice, meaning it cannot be tried again. She did not yet, however, rule on Arpaio’s request to throw out all the orders in the case. In other words, Arpaio wants the entire record cleared.

The Department of Justice, which had been prosecuting the case, adopted Arpaio’s position and agreed that the case should be dismissed and his record cleared. Ironically, the Justice Department’s website makes clear that a pardon cannot erase a conviction.

“Please also be aware that if you were to be granted a presidential pardon, the pardoned offense would not be removed from your criminal record,” a Justice Department page with frequently asked questions about presidential pardons reads.

In separate amicus briefs filed by legal groups and more than 30 House Democrats last month, the amici argued that even if the pardon were to stand, Bolton should not grant Arpaio’s request to vacate the rulings in his criminal case.

Once Bolton issues her final ruling, either side may choose to file an appeal. The fact that the Justice Department has sided with Arpaio complicates things, because it means the parties are not adversarial. The judge, however, may choose to appoint a private attorney to investigate and decide whether to appeal Bolton’s ruling. In fact, the federal rules of criminal procedure require the court to appoint private counsel to prosecute a contempt case, including an appeal, when the government declines to do so.

The reason is to maintain the separation of powers, said Ian Bassin, executive director of Protect Democracy, one of the amici that challenged the pardon, and former associate White House counsel to President Barack Obama.

“If the courts had to rely on the executive branch every time the court found someone in criminal contempt of court, the court would be subservient to the executive branch,” Bassin told The Intercept.

Although Bolton declined the amici’s request to appoint private counsel at the trial level, it’s not too late.

“Private counsel would essentially assume the role of the U.S. attorney for the purposes of the appeal,” said Brad Miller, a former North Carolina congressman and the author of a brief on behalf of nearly three dozen House Democrats challenging the pardon. “They would argue against the defendant’s motion — Arpaio’s motion to vacate the findings at the trial court level — and could have standing to file a notice of appeal to dispute the constitutionality of the pardon altogether. Judge Bolton did not rule our way on that, but she treated our constitutional concerns as serious, which they are.”

The Department of Justice is “exceedingly unlikely to advocate for the position we think a private attorney would be at least willing to consider,” Fein said. A private attorney would have the ability to file an appeal with the 9th Circuit, which is essential, the lawyers say, given the novelty of the circumstances surrounding Arpaio’s pardon.

“The consequence of this pardon, if it’s allowed to stand, is that courts would be deprived of power and be at the whim of the president to enforce our constitutional rights,” Bassin said. “A case of first impression cannot die at the district court level; that’s what appellate courts are for.”

Some House Democrats will likely join any subsequent challenge to the pardon, Miller said. “I fully expect if the issue goes up on appeal that all members who appeared as amici would also be willing to put their names on a brief that makes the same arguments to the 9th Circuit,” Miller said.