Podcast host Joe Rogan raised concerns during a recent episode over Democratic presidential candidate Joe Biden, saying that the former vice president’s alleged struggles were not a joke and should be taken seriously.

Rogan, a supporter of Sen. Bernie Sanders (I-VT), highlighted a clip from last week where Biden forgot the Declaration of Independence.

Biden said, “We hold these truths to be self-evident, all men and women created by, go, you know the, you know the thing.”

“Stop. Pause. He can’t be president,” Rogan responded. “Stop. Pause. Pause. Listen, we can’t play any games here, folks. This is a really old man who can’t talk. This is not a joke. Like that right now, ‘you know the thing,’ play that again. This should get you into a mental hospital. They should be like, ‘Hey, um, Joe are you alright?’”

Donald Trump Jr. highlighted the clip on Twitter, writing, “@joerogan says what everyone is thinking but no one in the media is willing to say because they hate Trump. Imagine someone sent him the other 1000 clips just as bad as this one from the last few weeks?”

WATCH:

.@joerogan says what everyone is thinking but no one in the media is willing to say because they hate Trump. Imagine someone sent him the other 1000 clips just as bad as this one from the last few weeks? pic.twitter.com/8Jmn4LbZ0F — Donald Trump Jr. (@DonaldJTrumpJr) March 8, 2020

During the Democratic presidential debates, Biden’s rivals have brought up his apparent struggles.

After one of the debates, then-candidate Sen. Cory Booker (D-NJ) criticized Biden over concerns that he couldn’t “carry the ball,” telling CNN, “I think we are at a tough point right now because there’s a lot of people concerned about Joe Biden’s ability to carry the ball all the way across the end line without fumbling. And I think that Castro had really legitimate concerns about can he be someone in a long, grueling campaign … and has every right to call out.”

“I think there were a lot of moments where a number of us were looking on the stage when he tends to go on sometimes,” Booker continued. “At one point, he was talking about communities like mine listening to record players. I don’t remember the last time I saw a record player … But there are definitely moments where you listen to Joe Biden and you just wonder …”

Sen. Cory Booker on Julián Castro's jab at former VP Joe Biden's memory: "Castro has some really legitimate concerns about, can he be someone in a long grueling campaign that can get the ball over the line? And he has every right to call that out." #DemDebate pic.twitter.com/rRxWIV0FmL — CNN (@CNN) September 13, 2019

TRANSCRIPT OF JOE ROGAN’S PODCAST: