Democratic New Jersey Sen. Cory Booker said Monday night that he occasionally has to resist urges of violence against President Donald Trump.

During an appearance on NBC’s “Late Night With Seth Meyers,” the 2020 presidential candidate poked fun at the president’s physique, adding that his “testosterone” sometimes makes him want to take a swing at Trump. (RELATED: Cory Booker: Free Health Care For Illegal Immigrants Is Just Common Sense)

“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,” Booker said to laughs from the audience.

After his initial comments, Booker continued to rip Trump’s appearance, calling the president a “physically weak specimen,” while at the same time calling Trump a “body-shamer,” and a “bully.”

“He’s the body-shamer, he’s the guy that shows — tries to drag people in the gutter,” Booker said.

The senator then pivoted to his campaign message, saying that Democrats have to demonstrate what they’re for, and not just what they’re against. (RELATED: 2020 Democrats Attack Joe Biden For Saying Segregationists Are Examples Of “Civility”)

“In this moral moment, we need not to talk about necessarily what we’re against, but what we’re for. And the best way of looking at this is just our history,” Booker said. The gardens of our democracy have never been free of the weeds of bigotry, hatred, demagoguery. Every generation has had them.”