Raul A. Reyes is an attorney and member of the USA Today board of contributors. Follow him on Twitter @RaulAReyes . The opinions expressed in this commentary are solely those of the author.This commentary has been updated from an earlier version to reflect news from a Wednesday hearing.

(CNN) On Wednesday in Phoenix, US District Judge Susan Bolton heard arguments relating to President Donald Trump's pardon of Joe Arpaio. Trump pardoned the former Maricopa County sheriff on August 25 , and the Department of Justice has dropped its case against him. The hearing was to decide whether Arpaio's conviction stands or is vacated -- thus closing an infamous chapter in Arizona history.

Right?

Not so fast. While Judge Bolton accepted Trump's pardon of Arpaio as legitimate, she did not rule on his request to have his record expunged. Nor should she expunge Arpaio's record.

There were genuine concerns regarding the legitimacy of Arpaio's pardon in the first place.

In 2016, Arpaio was found to be in civil contempt for refusing to obey a 2011 court order that he stop detaining people without the reasonable suspicion of a crime. In July, Bolton found him to be in criminal contempt for continuing these practices. Then came Trump's pardon, which many have viewed as motivated by politics and a simpatico worldview with the ex-sheriff, and now Arpaio wants his record wiped clean.

You don't have to be a lawyer to recognize that something about this process seems wrong; most Americans were against Trump pardoning Arpaio . The President pardoned Arpaio before he was sentenced, which was an unprecedented move. More broadly, this pardon can be read as the President endorsing racial profiling. And because it could allow Arpaio to escape any punishment for flouting the law, it also undermines the independence of the judiciary.

It could also result in more racial profiling of Latinos, if law enforcement officials believe there will be no consequence for such impermissible actions. The US Commission on Civil Rights has denounced it , while the American Bar Association noted that the pardon "sends the wrong message to the public."

Moreover, there was a legal case to be made that Arpaio's pardon should not stand. The presidential pardon power comes from Article II, Section 2 of the Constitution, which states that "the President ... shall have power to grant Reprieves and Pardons for Offences against the United States." But as Harvard law professor Laurence H. Tribe has pointed out, this does not mean unlimited power. Implicit in the pardon power is the principle that it shall not conflict with other parts of the Constitution.

Trump's pardon of Arpaio was suspect because it appears to violate the due process clause of the Fifth Amendment. Consider that for judicial review and due process to function, courts must be able to serve as a check on government officials. That would not be the case if Arpaio's pardon were allowed to stand, because Arpaio defied judges' orders.

And what about the Latinos whose civil rights were trampled on by Arpaio's immigration "sweeps" in predominantly Hispanic neighborhoods? This pardon deprives them of a lawful remedy for a violation of their rights, which means they would not receive equal protection under the law as guaranteed by the 14th Amendment.

Arpaio's pardon could have future implications, too. Harvard professor Tribe notes that the 1962 desegregation of the University of Mississippi depended on court orders for enforcement. Chipping away at such authority could have consequences in the future -- possibly setting the stage for Trump to pardon a close associate or family member in the event one is implicated in the probe of alleged campaign collusion with Russia.

in everyone's interest for Bolton to Surely there are liberals and conservatives who disagree on these legal arguments. That's why it wasin everyone's interest for Bolton to appoint a special prosecutor to argue against vacating Arpaio's conviction.

As things stand now, the judge will only be hearing from Arpaio's attorneys on why his conviction should be vacated. However, the constitutional questions raised by Arpaio's pardon deserve a full adversarial hearing. In fact, in cases such as this, where the government has declined to press forward with its case, federal rules say that "the court must appoint another attorney to prosecute the contempt."

There's another reason why a special prosecutor was necessary for an effective disposition of this case. Only a special prosecutor representing the United States could challenge the judge's decision on the pardon, which would allow the matter to go to the Court of Appeals or perhaps the Supreme Court for a final ruling.

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No matter where you stand on Arpaio's pardon, wouldn't you prefer that the matter be truly resolved? That can't happen absent a special prosecutor, which is why 33 congressional representatives have written to Bolton asking her to appoint one.

True, presidential pardons are often controversial. Remember Bill Clinton's pardon of fugitive financier Marc Rich , or George H.W. Bush's pardon of six figures in the Iran-Contra scandal ? Yet their offenses did not involve directly violating the constitutional rights of others. Nor were their pardons for crimes that originated within the judiciary. Arpaio's case represents uncharted territory and thus merits comprehensive legal scrutiny.

Although Judge Bolton declined to appoint a prosecutor to argue against Arpaio's pardon, his case should not be expunged from the record. That would have the legal effect of saying that the whole case against him had never occurred.

Department of Justice guidelines on presidential pardons specifically state that a pardon does not erase or expunge the crime for which the pardon was granted; even the President cannot erase someone's record this way. "Please be aware that if you were to be granted a presidential pardon, the pardoned offense would not be removed from your record," the DOJ website notes.

Going forward, the least that Judge Bolton can do is ensure that Arpaio's actions and conviction remain on the record, to remind us of how one person was able to violate his oath of office and abuse his lawful authority. To hold otherwise would be disrespectful to the judiciary -- as well as the Latinos whose civil rights were violated.