Democratic Sen. Cory Booker, who's running for president in 2020, on Monday told Seth Meyers that he sometimes thinks about punching President Donald Trump but wouldn't because it's not what a leader would do.

Booker in the process also critiqued Trump's physical appearance, calling him an " elderly, out-of-shape man" and a "physically weak specimen."

The New Jersey senator emphasized that he would not punch Trump because "you don't beat a bully like him fighting him on his tactics."

Booker said the US is facing a "moral moment" and needs a "leader that's not going to call us to the worst of who we are, but call us the best of who we are."

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Democratic Sen. Cory Booker of New Jersey on Monday said that he's sometimes contemplated punching President Donald Trump, but ultimately wouldn't because "you don't beat a bully like him fighting him on his tactics."

Booker, who's running for the 2020 Democratic presidential nomination, in an appearance on "Late Night with Seth Meyers" spoke about struggling with feelings of violent anger toward the president while emphasizing the importance of overcoming these sentiments.

The New Jersey senator, who noted he's a former tight end for the Stanford University football team, recalled a supporter in Iowa telling him that he wanted Booker to punch Trump in the face.

"He's a big guy, he puts his arm around me and goes, 'Dude, I want you to punch Donald Trump in the face,'" Booker said. "And I stop in my tracks and I go, 'Dude, that's a felony, man.'"

Booker went on to critique Trump's physical characteristics, which drew applause and laughter from the audience.

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"And, you know … Donald Trump is a guy who you understand he hurts you, and my testosterone sometimes makes me want to feel like punching him, which would be bad for this elderly, out-of-shape man that he is if I did that. This physically weak specimen," Booker said.

But the senator then made it clear that he wouldn't act on these feelings.

"But you see what I'm talking there? That's his tactics," Booker went on to say of Trump. "And you don't beat a bully like him fighting him on his tactics, on his terms, using his turf. He's the body-shamer, he's the guy that tries to drag people in the gutter."

Booker said the country is facing a "moral moment" and that what the country needs "from our next leader — especially after the time of moral vandalism that we're in right now — is we need a leader that's not going to call us to the worst of who we are, but call us the best of who we are."

The 2020 Democratic candidate's comments came as Trump continues to face a firestorm of criticism for racist tweets he sent last week at four progressive Democrats in Congress who are women of color.

The president has been unapologetic about his comments and is continuing his attacks on these lawmakers.

Trump, who's at times condoned violence at his rallies, has garnered a reputation for bullying his opponents and frequently attacks them publicly — often often via Twitter.