Hillary Clinton on Friday said that Donald Trump owed President Barack Obama an apology for spreading conspiracy theories that he wasn’t actually born in the United States.

“He’s feeding into the worst impulses, the bigotry and bias that lurks in our country,” Clinton said in a speech at the Black Women’s Agenda Symposium Workshop in Washington, D.C. “Barack Obama was born in America, plain and simple. And Donald Trump owes him and the American people an apology.”

Trump’s birtherism has re-emerged as a central issue in the 2016 race this week, after Trump refused to acknowledge that Obama was born in Hawaii.

Several of his campaign staffers have insisted he has renounced birtherism, however. His campaign released a statement Thursday saying that the real estate mogul deserved credit for highlighting the issue and, they claim, forcing Obama to release a long-form version of his birth certificate in 2011. Trump, who continued to suggest that the document was a forgery long after it was released, is expected to give a speech on Friday to address the issue.

Clinton said any statement Trump makes now can’t paper over the fact that he spread these conspiracy theories for years.

“As Maya Angelou once said, when someone shows you who they are, believe them the first time,” she said. “And we know who Donald is. For five years, he has led the birther movement to delegitimize our first black President. His campaign was founded on this outrageous lie. There is no erasing it in history.”

The Democratic nominee warned of the dangers of having “a person in the Oval Office who traffics in conspiracy theories and refuses to let them go no matter what the facts are.”

Clinton pivoted to Trump’s other attacks on minorities and women, accusing him of playing up Americans’ differences to “make us afraid of each other.”

“Donald Trump looks at a distinguished federal judge, born in Indiana, and he sees a Mexican, not an American,” she said. “He looks at a Gold Star family and sees them as Muslims, not patriotic Americans. He looks at women and decides how our looks rate on a scale of 1 to 10. I look at America. I see everyone. I see our great diversity, which is one of our core strengths.”