Ben Carson, the former neurosurgeon who is expected to enter the 2016 presidential race, called President Barack Obama a psychopath earlier this year in an overheard conversation.

Ben Carson On Obama

Earlier this year, when Obama was giving his sixth State of the Union, Carson, who was already feeling out a bid for the presidency, watched with derision. When conservative political commentator Armstrong Williams noted, “He looks good. He looks clean. Shirt’s white. The tie. He looks elegant,” Carson had a scathing retort.

“Like most psychopaths. That’s why they’re successful,” Carson said, according to GQ. “That’s the way they look. They all look great.”

When Williams later noted that Obama was trying to sell his narrative of America’s future, something that Carson will have to do once he starts campaigning in earnest, Carson had more harsh words for the president.

“He knows he’s telling a lie!” Carson said. “He’s trying to sell what he thinks is not true! He’s sitting there saying, ‘These Americans are so stupid I can tell them anything.'”

Carson has received ample backlash since he started speaking publicly on political matters with inflammatory rhetoric. Earlier this month, Carson took to Facebook to apologize after declaring that being gay is a choice, claiming, “because a lot of people who go into prison go into prison straight, and when they come out, they’re gay.”

Carson has also gone on record to declare Obamacare the worst thing to happen to the United States since slavery and to compare modern America to Nazi Germany.

Despite his polarizing language, Carson, who has never run for office, remains a contender in the field of potential Republican presidential candidates.