Former sheriff Joe Arpaio, who’s running for Senate in Arizona on a pro-Trump platform, told a small gathering at last weekend’s Western Conservative Conference in Phoenix that while he’s “kind of dropping” his birther claims about President Obama while he campaigns, he’ll start bringing them up more if he’s elected to the Senate because “100 percent we proved” that the former president’s birth certificate is “a fake document.”

In a speech to a small group at the event, which was posted on YouTube by the channel Tru Conservative TV, Arpaio recalled introducing Trump at a campaign rally in 2015 where he spoke about his and Trump’s shared interest in cracking down on immigration and in investigating Obama’s birth certificate. (Trump pardoned Arpaio this summer after he was convicted of contempt of court.)

“I talked about another thing that made a little news,” Arpaio said. “I don’t talk about it anymore—until I become the U.S. senator…but that’s something to do with a document. If I ask you guys—I’m a nothing now, but if I was still the sheriff I could ask for your birth certificate.”

“So I’m kind of dropping that right now,” he said, “but I’m going to tell you something: 100 percent we proved that’s a fake document. One hundred.”

In the small crowd surrounding Arpaio was Dave Giles, a Republican candidate for a Phoenix-area House seat.