Former President Trump’s onetime White House press secretary told delegates at the Democratic National Convention on Tuesday that Trump, when out of the public eye, would mock his supporters and refer to them as “basement dwellers.”

Stephanie Grisham, who said she would be voting for Vice President Kamala Harris, began her remarks at the United Center in Chicago by saying, “I wasn’t just a Trump supporter. I was a true believer — one of his closest advisors.”

She likened the Trump family to her own family and recounted spending Easter, Thanksgiving, Christmas and New Year’s at Trump’s Florida estate, Mar-a-Lago. But then she addressed Trump’s character.

“I saw him when the cameras were off,” Grisham said. “Behind closed doors, Trump mocks his supporters — he calls them ‘basement dwellers.’ On a hospital visit one time, when people were dying in the ICU, he was mad that cameras were not watching him. He has no empathy. No morals. And no fidelity to the truth.”

Grisham is among a handful of Republicans appearing at the convention to denounce Trump and endorse Harris.

To applause, Grisham said she was the first senior White House staffer to resign on Jan. 6, 2021, the day Trump supporters stormed the Capitol and tried to block the certification of Joe Biden’s election victory. “I couldn’t be part of the insanity any longer,” she said.

Referring to Trump, she added, “He used to tell me, ‘It doesn’t matter what you say, Stephanie. Say it enough, and people will believe you.’ But it does matter. What you say matters — and what you don’t say matters.”

Grisham said that when she was press secretary, she “got skewered for never holding a White House briefing. It’s because, unlike my boss, I never wanted to stand at that podium and lie.”