Presidential candidate Pete Buttigieg has clapped back after Donald Trump gave him an unflattering but somewhat archaic nickname.

“Alfred E. Neuman cannot become President of the United States,” Trump told Politico Friday, referring to Mad magazine’s youthful and goofy mascot.

“I’ll be honest, I had to Google that. I guess it’s just a generational thing,” Buttigieg later told Politico, throwing subtle shade at the president’s advanced age. “I didn’t get the reference. It’s kind of funny I guess, but, uh, he’s also the President of the United States and I’m surprised he’s not spending more time trying to salvage this China deal.” Trade talks between the United States and China ended Friday in Washington, D.C. without an agreement.

Mad, a satirical publication founded in 1952, has often lampooned Trump on its covers.

Trump made his first public attack on Buttigieg Wednesday during a Florida rally, seemingly criticizing the candidate’s perceived weakness. “We have a young man, Buttigieg,” he told the crowd of his 2020 competition, mocking the pronunciation. “He’s got a great chance doesn’t he? He’ll be great. He’ll be great, representing us against President Xi of China. I want to be in that room, I want to watch that one.”

Buttigieg responded: “You can’t get too worried about the name-calling and the games he plays. I was thinking of a Chinese proverb that goes, ’when the wind changes, some people build walls and some people build windmills.’ You gotta recognize that we need something that is completely different from what is in this White House. The negotiations that they are conducting, whether it’s on trade or things like North Korea, are usually a personal high-wire act with no safety net.”

Trump acknowledged last month that he would “like running against” Buttigieg in 2020.

The 37-year-old South Bend mayor officially announced his bid last month to become the youngest and first openly gay president of the United States.

Born in South Bend, Indiana’s fourth largest city with roughly 100,000 residents, Buttigieg is a Harvard graduate, a Rhodes scholar, and a veteran Naval lieutenant who served in Afghanistan. He was elected mayor in 2011 and, despite governing as a progressive Democrat in a very red state, was reelected for a second term.

Scott Olson/Getty Images

Buttigieg came out publicly as gay in an open letter printed in the South Bend Tribune in 2015, shortly before the Supreme Court’s ruling on federal marriage equality, making him Indiana’s first openly gay executive and that state’s highest elected official to come out.

He married his longtime partner, teacher Chasten Glezman, last summer.

Celebrity interviewer. Foodie and Broadway buff in Manhattan. Hates writing bios.

@brandonvoss