During Friday’s episode of his HBO show “Real Time,” Bill Maher revealed why he’s “very nervous” that Joe Biden will lose to President Donald Trump.

While talking to MSNBC host Joy Reid, Maher said that he thinks that the Republican National Convention’s optimism will prove very effective, and will cause enthusiasm for Biden to tank.

“I don’t know if this stuff works, but it might,” Maher said. “I am feeling less confident about this — maybe it’s just their convention bump got to me, but I’m feeling less confident than I was a month ago.”

Maher went on to say that the GOP’s strategy of presenting diversity —in the face of the DNC emphasizing conformity— has caused him to question Biden’s electability.

“People do have their own minds. I’ve never been a fan of conformity. I’ve never been a fan of, ‘We all wear pink on Wednesday,’ we all have to do this, we all have to say this, we all have to do this then,” Maher said. “I don’t bend the knee and I get that people are pushing back at that kind of stuff.”

“I feel very nervous, the same way I did four years ago at this time,” he added.

Maher then said that the optics of Trump’s nomination acceptance speech, which was given at the White House with an audience that did not conform to face mask requirements, will likely resonate with the American people.

“To portray that idea that ‘I would rather die on my feet than live on my knees,’ yes, I think that is attractive to a degree,” Maher explained. “They looked optimistic, they looked like the country isn’t falling apart, even though the country is falling apart. And optimism very often wins elections.”

This comes after it was revealed that Biden’s lead over Trump had shrunk after the RNC. Before the convention, Biden led by a 10-point margin, 52% to 42% among likely voters. Since then, Biden’s lead has shrunk by four points, as he now only leads by a six-point margin: 50% to 44%.