WATCH: Joe Arpaio still insists he has evidence of Obama's 'phony' birth certificate — and says we're 'gonna hear more about it'

When asked by CNN host Chris Cuomo about his chance to reinvent himself before Arizona voters amid his 2018 Senate run, Sheriff Joe Arpaio doubled down on his insistence that former President Barack Obama was not born in the United States — and .

After invoking Frank Sinatra's "My Way" by claiming he has "too few" regrets to mention regarding his bigoted immigration enforcement record, Arpaio admitted he'd made "a few mistakes."

"Was the birtherism a mistake?" Cuomo asked.

"Oh, now you're bringing that up?" the pardoned former sheriff responded.

"I started this because of a fake government document," Arpaio said of his insistence that Obama was not a true American citizen. "I didn't care where the president came from. I didn't care at all. We had the evidence, nobody will talk about or a look a at it. Anytime you want to come down, we'll be glad to show you the evidence. You're going to hear more about this."

"You think President Obama's birth certificate is a phony?" the host reiterated.

"No doubt about it," the ex-sheriff responded. "We have the evidence. I'm not going to go into all the details. It's a phony document."

Cuomo reminded Arpaio that "even Donald Trump says he now believes Obama was born in this country."

"If you want to be a U.S. senator, don't you think that people should have confidence in your judgment on something as crucial as that?" the host implored.

Watch below, via CNN: