A day after Joe Arpaio officially launched his bid to be the next U.S. senator from Arizona, the controversial former sheriff returned to a polarizing question that was seemingly put to bed in public by his party’s own standard-bearer:

Where was Barack Obama really born? 

Arpaio told CNN’s Chris Cuomo on Wednesday that he still thinks Obama’s birth certificate is fake, even though the biggest fanner of the birther flame — President Trump — said in 2016 that he believes Obama was born in Hawaii, not Kenya.

“You believe that President Obama’s birth certificate is a phony?” Cuomo asked on his CNN show Wednesday night.

“No doubt about it. No doubt about it,” Arpaio replied, seemingly aggrieved about Cuomo bringing the issue up. “We have the evidence.”

He added: “I’m not going to go into all the detail, but yes, it’s a phony document.”

Arpaio — once dubbed “America’s Toughest Sheriff,” for his heavy-handed immigration tactics and harsh treatment of criminals and suspects in his jails  — is running in the 2018 Republican primary to determine who will replace Republican Sen. Jeff Flake.

The 85-year-old Arpaio is a longtime Trump supporter who spoke at the Republican National Convention.

As The Washington Post wrote in 2017, the pair have similar views on immigration and law enforcement.

They also once viewed the birtherism “debate” from the same place: Obama, they agreed, wasn’t born in the United States, and therefore wasn’t eligible to be president of the United States.

During the final months of the 2016 presidential campaign, Trump told The Post in an interview that he remained unwilling to say that Obama was born in the United States.

As The Post’s Robert Costa wrote on Sept. 15, 2016, following an interview on Trump’s private plane:

Trump suggested he is not eager to change his pitch or his positions even as he works to reach out to minority voters, many of whom are deeply offended by his long-refuted suggestion that Obama is not a U.S. citizen. Trump refused to say whether he believes Obama was born in Hawaii.

“I’ll answer that question at the right time,” Trump said. “I just don’t want to answer it yet.”

When asked whether his campaign manager, Kellyanne Conway, was accurate when she said recently that he now believes Obama was born in this country, Trump responded: “It’s okay. She’s allowed to speak what she thinks. I want to focus on jobs. I want to focus on other things.”

He added: “I don’t talk about it anymore. The reason I don’t is because then everyone is going to be talking about it as opposed to jobs, the military, the vets, security.”

Hours later, though, Trump’s campaign said in a statement that he no longer doubted Obama’s birth in Hawaii and that Trump had done “a great service to the President and the country” by prompting Obama to release his long-form birth certificate in 2011.

But, as Costa noted, the campaign “also repeated the widely debunked claim that [Hillary] Clinton and her campaign had questioned Obama’s birthplace in 2008, which is false.”

The following day, The Post’s Jenna Johnson reported that Trump himself acknowledged for the first time that Obama was born in the United States, ending his long history of stoking unfounded doubts about the nation’s first African American president.

“President Barack Obama was born in the United States. Period,” Trump said, though he repeated the falsehood that Clinton and her unsuccessful 2008 campaign started the birther controversy.

(That same day, Obama told reporters he was “pretty confident about where I was born.”)

Trump has never publicly changed his position, though the New York Times reported in November that advisers said Trump, in recent months, had “used closed-door conversations to question the authenticity of President Barack Obama’s birth certificate.”

Arpaio, for his part, has been unwavering in his belief that Obama’s birth certificate isn’t real.

In December, shortly before leaving the Maricopa County Sheriff’s Office, Arpaio announced that his “Cold Case Posse” had found “9 points of forgery” following a five-year investigation of the birth certificate, according to the Arizona Republic.

Arpaio pushed the theory that someone copied and pasted Obama’s information onto the birth certificate of a woman born in Hawaii.

Arpaio gained national notoriety for forcing inmates to wear pink underwear, eat meatless meals while the Food Channel was broadcast in the jail cafeteria and, for a quarter century, sleep outdoors in a “tent city jail” made of Korean War era canvas.

But he was sentenced to jail for his immigration tactics.

In 2011, as part of a lawsuit, a federal judge said Arpaio could no longer detain people he thought were illegal immigrants who had not been convicted of a crime. But he ignored the judge’s order and, in 2016, the U.S. Justice Department pursued a criminal contempt case against him. A year later he was convicted, but before Arpaio could serve a day in jail, Trump pardoned him.

“Arpaio’s life and career, which began at the age of 18 when he enlisted in the military after the outbreak of the Korean War, exemplify selfless public service,” Trump said in a statement announcing the pardon. “Throughout his time as Sheriff, Arpaio continued his life’s work of protecting the public from the scourges of crime and illegal immigration.

“Sheriff Joe Arpaio is now eighty-five years old, and after more than fifty years of admirable service to our Nation, he is worthy candidate for a Presidential pardon,” the statement added.

But voters had rejected Arpaio months before that. He was unseated by Paul Penzone, a veteran police officer who promised to be tough on crime without racially profiling people or violating their constitutional rights. As The Post’s Ben Guarino wrote, Arpaio had trailed Penzone in the polls by double digits in a Maricopa County that had become more liberal, with more Latino and young voters. Arpaio lost by 130,000 votes.

As The Post’s Dave Weigel wrote, Democrats thought that defeat — followed by the conviction — was the end of Arpaio’s political life.

This week, they were using his entry into the Senate race to garner support and donations.

The turnout group Vote Latino sent a message to donors. It said Arpaio should in “no way, shape or form be anywhere near our government.”

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