Police may make an arrest if they have probable cause to believe a crime has been committed. But what if an arrest for which there is probable cause is really designed to punish a citizen for exercising his right to free speech under the First Amendment?

On Tuesday the Supreme Court rightly ruled that at least some such arrests can be challenged as civil rights violations, even as it rejected the particular claim before it.

In a majority opinion joined in full by four other justices, both liberal and conservative, Chief Justice John Roberts said that Russell P. Bartlett could not pursue a lawsuit against Alaska state troopers who arrested him in 2014.

Bartlett was arrested on charges of disorderly conduct and resisting arrest at Arctic Man, an extreme ski and snowmobile event in the Hoodoo Mountains that Roberts drolly described as “an event known for both extreme sports and extreme alcohol consumption.”

The troopers claimed that Bartlett was drunk and disorderly and that he interfered in the questioning of a teenager about whether he and his underage friends had been drinking. Bartlett denied that he was drunk or disorderly. He said that the real reason he was arrested was that he refused to speak to one of the troopers and criticized the other. Bartlett said that when he was arrested and handcuffed, the first trooper said, “Bet you wish you would have talked to me now.”

In ruling against Bartlett, Roberts said that, as a general matter, plaintiffs alleging that an arrest was retaliation for the exercise of free speech must prove that the decision to press charges wasn’t supported by probable cause.

But Roberts allowed for an important exception: Such lawsuits can go forward in situations “where officers have probable cause to make arrests, but typically exercise their discretion not to do so.” Roberts offered the example of a vocal critic of the police who is arrested for jaywalking even though arrests for that offense are rare.

Last year the justices ruled that a citizen who was arrested at a public meeting could pursue a lawsuit based on the assertion that his arrest, even if justified by probable cause, was the result of a conspiracy by local officials to retaliate against him for his prior public criticisms of city officials. But that decision was a narrow one that didn’t address most cases of alleged police retaliation. Tuesday’s ruling – even though Bartlett lost – seems to allow lawsuits against the police in additional circumstances.

Still, the majority didn’t go far enough. In a dissenting opinion, Justice Sonia Sotomayor persuasively argued that ulterior motives in an arrest could be demonstrated even if police customarily made arrests on a particular charge. For example, a retaliatory motive might be established through a police officer’s own incriminating statements about his or her motivation.

Some might ask why any arrest that is supported by probable cause should be second-guessed in a civil rights lawsuit. The answer is simple: Police in this country sometimes abuse their authority and act with ulterior motives, such as racial animus or a desire to punish someone who “mouths off” and expresses an opinion the officer doesn’t want to hear. That can be the case even if the officer can point to probable cause to make an arrest.

Police officers have a difficult job, and sometimes their patience is tried by citizens who don’t show them respect. But what some call “contempt of cop” is protected by the First Amendment. Police shouldn’t be able to retaliate for such criticism by arresting the critics.