Former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Amy Klobuchar (D-MN) got into a heated exchange at the Democrat presidential primary debate in Las Vegas, Nevada, on Wednesday after Klobuchar was questioned on her mishap of not knowing the president of Mexico’s name.

During a Telemundo interview last week, three of the Democrat presidential hopefuls including Klobuchar, Buttigieg, and billionaire Tom Steyer, were asked who the president of Mexico is. Buttigieg was the only candidate questioned who could correctly name President Andrés Manuel López Obrador.

Buttigieg brought up the issue Wednesday night as he stood alongside Klobuchar on the debate stage.

“You’re on the committee that oversees border security. You’re on the committee that does trade. You’re literally part of the committee that’s overseeing these things,” Buttigieg said as he named some of Klobuchar’s duties as a senator.

Buttigieg also noted that Klobuchar was “not able to speak to literally the first thing about the politics of the country” she was questioned about.

“Are you trying to say that I’m dumb,” Klobuchar asked Buttigieg. “Are you mocking me here, Pete?”

“He’s basically saying that I don’t have the experience to be president of the United States,” Klobuchar added.

Former Vice President Joe Biden was quick to interject between the two and said, “I’m the only one who knows this man! I met with him!”