Democratic vice presidential candidate Sen. Tim Kaine responded to Republican Donald Trump’s shifting positions on immigration partially in Spanish by calling him an “idiota.”

Kaine made the remark Thursday night in an appearance on “The Late Show With Stephen Colbert” on CBS. Colbert had asked Kaine to respond to Trump calling Democratic rival Hillary Clinton a bigot.

Kaine pointed out that Clinton started her career pushing for racial justice in the juvenile justice system in South Carolina and fighting school segregation in Alabama while Kaine himself battled “housing discrimination in the South and in Virginia” when he got out of law school.

“At his early career, Donald Trump was a real estate guy who got sued by the Justice Department for discriminating against people in housing, writing the letter ‘C’ on applications if they were a minority” he said.

During the interview, Colbert leaned forward and with mock concern asked about Clinton’s health, appearing to poke fun at Trump and a few Republicans who’ve tried to make it an issue.

“I think she could beat me in the New York Marathon if we entered,” Kaine replied.

After the interview, Kaine, who carries around four harmonicas, jammed with Colbert’s band, Stay Human.