Cher was the headline speaker at an LGBT fundraiser on Monday for presidential candidate Joe Biden.
According to the Washington Blade, 500 people attended the virtual event and it raised $2 million for the Biden campaign.
Cher was joined at the event by Rhode Island Representative David Cicilline, Wisconsin Senator Tammy Baldwin, and former presidential candidate Pete Buttigieg. The three politicians are openly gay.
Cher said that she met Biden in 2006.
"He thinks he invited me but really I invited myself [to his office]. I saw a speech Joe had given and it was love at first speech," Cher said. "Joe actually listened to me and cared [about] what I had to say. He was honest and kind and smart."
"I also know that the person, woman, man, camera, TV in the White House is an idiot," she said, referring to President Donald Trump's boasting of passing a cognitive test.
Cher also criticized Trump's attacks on the transgender community. Cher's son, the actor Chaz Bono, is transgender.
Biden reiterated his commitment to passing the Equality Act, a federal LGBT protections bill that stalled in the Senate after it cleared the House. Trump has signaled his opposition to the bill.
"I'll make signing the Equality Act one of the top priorities of my first 100 days," Biden said, adding that he would "build a nation where everybody, everybody is finally not only created equal but treated equally as well."