President Trump’s pardon of former Sheriff Joe Arpaio has set off a new round of recriminations, with Republicans saying they disagreed with the decision and Democrats saying it was an unforgivable abuse of power that presages still more political mischief.
Several anti-Trump lawmakers said the president was sending a signal to the Justice Department — and even to special counsel Robert Mueller, investigating Russian meddling in the election — that he is willing to go to great lengths to protect political allies.
Immigrant rights activists, meanwhile, said the president’s pardon was dismaying for Hispanics who for years had protested the sheriff of Maricopa County, Arizona, and who mobilized en masse last year to defeat Mr. Arpaio, who was seeking a seventh term in office.
“It is disheartening that [the president] set the bar so very low for his first pardon,” said Sen. Patrick J. Leahy of Vermont, the senior Democrat in the Senate. “It is a shame to see the pardon power devalued like this. The ex-sheriff is a self-aggrandizing braggart who promoted racist law enforcement practices and cost taxpayers millions, and that is a reason they did not re-elect him.”
Mr. Trump granted Mr. Arpaio the first pardon of his presidency and announced the move late Friday.
It short-circuits the case against Mr. Arpaio, who was convicted this year of criminal contempt of court. The judge who convicted him said he willfully ignored another judge’s 2011 order halting the sheriff’s traffic-stop program, which identified illegal immigrants who were then turned over to federal deportation authorities.
The court said the program unlawfully profiled Hispanics in the county, and said Mr. Arpaio refused to comply with the order halting it.
Mr. Arpaio had yet to be sentenced, his attorneys were challenging the conviction on multiple grounds and vowing an appeal if they couldn’t get the verdict tossed, and the former sheriff hadn’t even formally requested a pardon.
“I’m very appreciative of what the president has done,” Mr. Arpaio told NBC News after the pardon was announced. “Right now, I have to thank the president for standing by me and standing by law enforcement. And I’m very humbled.”
The last administration instituted a policy of requiring pardons to be vetted by the Justice Department before President Obama would grant them. Mr. Obama set records for clemency in cutting sentences of drug dealers and users and repeat felons — including those who used guns in the commission of their crimes.
Mr. Obama also issued end-of-term decisions to commute sentences of a member of a Puerto Rican terrorist group, and of Chelsea Manning, who before undergoing sex-change surgery was Army Pvt. Bradley Manning, serving 35 years in prison for leaking government secrets to WikiLeaks.
Mr. Trump’s first pardon signals he won’t be beholden to the Justice Department process that Mr. Obama followed.
Rep. Adam B. Schiff, California Democrat, said it also signals to Mr. Trump’s allies from the campaign that he may rescue them from political jeopardy from Mr. Mueller’s probe into the November election. A number of Trump campaign figures are potentially under scrutiny for dealings with Moscow.
“The concern I have is that he’s sending a message to people that may be under investigation by Bob Mueller that I have your back and I’ve got a pardon waiting for you,” Mr. Schiff said on MSNBC. “So I am concerned about that because obviously this is a president who is not above using the pardon power strictly in his own very narrow personal interest.”
But Mark Corallo, a veteran Republican consultant who worked for Mr. Trump’s legal team this year, said he doesn’t believe the pardon foreshadows anything about the special counsel investigation.
“The Arpaio pardon was an easy call on the politics,” Mr. Corallo said. “The Trump haters are going to keep hating him regardless. The president’s base approves of it wholeheartedly. The people in the middle are not concerned with it.”
He added, “The president was fully within his authority to issue this or any pardon. Regardless of whatever process exists at DOJ, the constitution grants the president plenary power to pardon anyone. The remedy for those who disagree with the pardon is at the ballot box.”
Still, many Republican lawmakers chastised Mr. Trump for the move. Sen. John McCain, an Arizona Republican who had tangled with Mr. Arpaio, led the charge.
“Mr. Arpaio was found guilty of criminal contempt for continuing to illegally profile Latinos living in Arizona based on their perceived immigration status in violation of a judge’s orders,” said Mr. McCain. “The president has the authority to make this pardon, but doing so at this time undermines his claim for the respect of rule of law as Mr. Arpaio has shown no remorse for his actions.”
The office of House Speaker Paul D. Ryan, Wisconsin Republican, also said he disagreed with the pardon.
But Mr. Trump got support from another Arizona Republican, Rep. Trent Franks, who had urged Mr. Trump to take the step.
Mr. Franks said the pardon was neither unprecedented nor outrageous, as critics suggested, and he compared it favorably with Mr. Obama’s commutation of Manning’s sentence.
“While no one can dispute Manning acted to undermine our country’s national security, Joe Arpaio has spent a lifetime trying to maintain it. Comparing the two, it is easy to discern that Arpaio is a patriot while Manning is a traitor,” Mr. Franks said.
Tom Bossert, Mr. Trump’s homeland security and counterterrorism adviser, brushed aside accusations that the president hid the Arpaio pardon behind Hurricane Harvey, which was preparing to make landfall in Texas as the pardon was announced.
“I think the Arpaio pardon is pretty straightforward,” Mr. Bossert said on ABC’s “This Week” program. “Just about every modern president ends up with some controversial pardons, but I think the president’s been pretty clear on it and I certainly don’t think it’s fair to characterize him as not caring about the rule of law.”
• Stephen Dinan contributed to this report.