Then-Republican presidential candidate Donald Trump with Joe Arpaio. (Mary Altaffer/Associated Press)

EVEN AS President Trump urges the nation to heal, he is publicly considering a step whose effect would be the exact opposite: a pardon for former sheriff Joe Arpaio, the former Arizona lawman who made his name as a paragon of racial profiling.

Pardoning Mr. Arpaio now would throw a bone to the president’s partisans on the racist alt-right just days after Mr. Trump fed them a juicy steak by explicitly equating the neo-Nazis, anti-Semites and Ku Klux Klansmen in Charlottesville with those who marched against them. If Mr. Trump wants to further inflame and divide America, there would be few more effective ways to do it than by granting clemency to a man whose political career was based on contempt for Latinos generally and Hispanic undocumented immigrants specifically.

A pardon for Mr. Arpaio, convicted of criminal contempt of court just three weeks ago, would circumvent the Justice Department’s long-established procedure for review. The former sheriff, whose sentencing is scheduled for October, hasn’t even applied for a pardon, the processing and consideration for which would ordinarily take several years. Thousands of applications have yet to be reviewed.

Yet Mr. Trump has said he is considering such a move. After all, the president and the former sheriff, an early and enthusiastic backer of Mr. Trump’s candidacy, are two peas in a nativist pod. Both were ardent “birthers” who questioned whether Barack Obama was born in the United States, a touchstone of actual “fake news”; both maligned Hispanic judges, attacking their legitimacy on grounds of ethnicity; both are unapologetic champions of racial profiling. (“Well, we have no choice,” said Mr. Trump, defending the practice.)

Mr. Arpaio was found guilty of having ignored a federal court order directing him to halt a campaign of illegal arrests and detentions based on suspects’ appearance — in other words, explicit racial profiling. Thumbing his nose at the order, he continued the prohibited patrols for an additional 17 months and bragged about it to voters in Arizona’s Maricopa County.

Former Maricopa County, Ariz., sheriff Joe Arpaio ignored a judge’s order to stop detaining people because he merely suspected them of being undocumented immigrants. (Thomas Johnson/The Washington Post)

Generally, presidential pardons are granted after a decent interval to individuals who have expressed contrition for their offense. By contrast, Mr. Arpaio has dismissed his prosecution as politically motivated and sneered at the charge on which he was convicted as a “petty crime” of which he is “100 percent not guilty.”

Even as Mr. Trump was busy last week condoning the goons and thugs who invaded Charlottesville — there were “very fine people” among them, the president said — he was praising Mr. Arpaio for his “crackdown” on illegal immigration and saying he was seriously considering a pardon for him. “He’s a great American patriot, and I hate to see what has happened to him,” Mr. Trump said.

To say such a thing is to twist the meaning of patriotism. Mr. Arpaio, who used ethnicity as a wedge issue and delighted in humiliating the immigrants he arrested and incarcerating them in inhumane conditions, is no more a patriot than the thugs in Charlottesville are. Pardoning him would be a travesty of justice that would further discredit a presidency already stained by Mr. Trump’s words and conduct.