Between when Trump verbally committed to pardoning former Sheriff Joe Arpaio and when he actually did so last night, law professor Martin H. Redish of Northwestern University wrote a piece for the New York Times about the parameters of the presidential pardon power. What are the limits, and what can be done if the power is clearly abused?

Many legal scholars argue that the only possible redress is impeachment — itself a politicized, drawn-out process. But there may be another route. If the pardon is challenged in court, we may discover that there are, in fact, limits to the president’s pardon power after all.

The only effective means courts have to prevent or stop governmental violations of constitutional rights is through injunctions. But injunctions have teeth only when they have the potential of a contempt conviction behind them. In other words, in issuing an injunction, a court is saying, “stop doing that or else.” The “or else” is a criminal conviction for contempt, leading to a fine, imprisonment or both. Absent the “or else,” the injunction is all but meaningless.

But if the president signals to government agents that there exists the likelihood of a pardon when they violate a judicial injunction that blocks his policies, he can all too easily circumvent the only effective means of enforcing constitutional restrictions on his behavior. Indeed, the president could even secretly promise a pardon to agents if they undertake illegal activity he desires.

In one sense, the pardon power pertains to any “offense” against the United States, and therefore would seem to cover anything that might happen in a federal court that brings punishment. Show up late to court and get slapped with contempt? Tell the judge to screw herself in the ear? Deliberately urinate on the floor? All of it can be construed as an “offense” against the United States’ federal government. But, as Prof. Redish notes, these aren’t things that bring people into court in the first place. They can be done as easily by the lawyers or the plaintiff as they can be done by the defendants. The court has the power to impose order and rules on its courtroom and on the procedure with which the trial will proceed. They can demand that jurors don’t talk to each other or that lawyers don’t talk to the press. They can demand that defendants not engage in certain behaviors or that police not enforce certain crimes while the issues at hand are adjudicated. These are more process issues than matters of guilt or innocence.

If we let the president pardon people for these types of things, we let the president interfere in the administration of justice, and there is at least an argument to be made that this was not the intent of the pardon power in the Constitution.

Arpaio’s case is a little more complex than this. It has recently been established that people who are accused of criminal contempt of court, as Arpaio was, can get a jury trial if the penalty is potentially more severe than six months. The idea is that anything less than six months is for “petty crimes” but a longer sentence shouldn’t be imposed without the defendant getting an actual trial with all the rights attendant to that. This is an effort to strike a balance between letting judges impose order and not letting judges mete out long, harsh punishments without the oversight and approval of a jury. Arpaio was only facing six months in prison, so by precedent he did not deserve a jury trial and he lost his appeals in his effort to get one.

But it could be argued that since at least some criminal contempt cases are treated as actual trials instead of mere matters of court administration that the whole category qualifies as an offense against the United States.

My point here is that this stuff could be litigated to explore where the lines might be drawn limiting the presidential pardon power. The Courts will not want to grant the president the power to contravene their court orders. It’s obviously recognized that the president can nullify the sentence imposed after a trial or even to preemptively pardon a crime that hasn’t even come to trial (as President Ford did in the case of Richard Nixon). And that can be interpreted to allow anything, no matter how abusive and corrosive to the administration of justice. But it’s also possible that the Courts could argue that offenses against the Court are not synonymous with offenses against the United States. An offense against the United States could be defined as an original charge brought by a prosecutor rather than a charge arising out of a trial. Perhaps the same distinction used to determine eligibility for jury trials in criminal contempt cases could be carried forward for presidential pardons.

If so, the only limitation on the pardon power would be for cases of contempt that carry a penalty of six months or less, but it would protect the integrity of the court system and prevent the president from orchestrating a systematic scheme to ignore and abuse people’s civil rights.

Likewise, we may soon have to litigate if there are any remedies short of impeachment for a president who pardons witnesses for the purpose of obstructing an investigation against himself, or whether a president can pardon themselves for crimes they have committed.

The Courts are an independent branch of the federal government and they have the ability to fight back against a rogue president. The pardon power provided in the Constitution is explained in incredibly succinct language: “he shall have Power to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment.”

The only wiggle room in there seems to be over how we define “offenses.” We’ve never had to decide exactly what that means before, but I think now we do.

Beyond the semantics, there’s also common sense. Is it plausible that the authors of the Constitution intended to give the president the authority to commit crimes with impunity, to obstruct investigations into his own conduct with his power to grant preemptive pardons? We know that they provided impeachment as a remedy for these types of behaviors, but it would to make sense to draw some lines around how much mischief a president can create.

One thing seems absolutely clear to me. Even under the broadest possible interpretation of the presidential pardon power, a clear abuse of the privilege is possible and since the only remedy (in this interpretation) is impeachment, the abuse would have to be grounds for impeachment.