Republican presidential nominee Donald Trump returned to a favorite topic on Thursday — whether President Barack Obama was, in fact, born in Hawaii, as has long been a settled matter of fact.

But in a swaggering interview with The Washington Post, Trump refused to concede that Obama was born in the United States, touching off a firestorm that barely died down, even after his campaign issued a statement a short while later saying Trump “believes that President Obama was born in the United States.”

The statement — not quoting Trump but a senior communications adviser — did little to stop Democratic nominee Hillary Clinton from unleashing a withering rebuke in her first day back on the campaign trail after spending several days recovering from pneumonia.

“When will he stop this ugliness, this bigotry,” she asked, speaking to the Congressional Hispanic Caucus Institute awards gala in Washington, D.C. “He’s tried to reset himself and his campaign many times. This is the best he can do. This is who he is, so we need to decide who we are.”

Her national campaign spokesman, Brian Fallon, said the Trump campaign statement was insufficient.

Trump needs to say it himself. On camera. And admit he was wrong for trying to delegitimize the country’s first African American President

— Brian Fallon (@brianefallon) September 16, 2016