Sen. Tim Kaine, D-Va., used his time on the "Late Show" with Stephen Colbert Thursday to push back on GOP nominee Donald Trump's claim that Hillary Clinton is a bigot.

"When Hillary Clinton got out of law school, she was working to help advance racial justice in the juvenile justice system in the south, segregation in Alabama," Kaine told the show's host. "And I about that time got out of law school, was battling housing discrimination in the south in Virginia.

"At his early career, Donald Trump was a real estate guy who got sued by the Justice Department for discriminating against people in housing," the Virginia senator added. "Hillary Clinton has got a track record all the way back to being a middle schooler in trying to advance priorities for others. Donald Trump is for himself."

Kaine also said he didn't buy reports suggesting that Trump had softened on his immigration stance.

"I don't buy it," Clinton's running mate said flatly.

Trump declared at a campaign rally in Jackson, Miss., Wednesday evening that Clinton is a bigot whose polices take advantage of minority voters.

"Hillary Clinton is a bigot who sees people of color only as votes, not as human beings worthy of a better future!" he said. "She's only going to take care of herself, her husband, her consultants, her donors – these are the people she cares about."

Though Trump has previously referred to Clinton's policies as being bigoted against minority voters, Wednesday marks the first time that he has accused the Democratic nominee herself of being a "bigot."

Clinton also dismissed Trump's "bigot" attack in a winding speech Thursday that saw her accusing the Republican candidate of peddling bigotry and paranoia.

"Donald Trump has built his campaign on prejudice and paranoia," she said at a campaign rally in Reno, Nev. "He is taking hate groups mainstream, and helping a radical fringe take over the Republican Party. His disregard for the values that make our country great is profoundly dangerous."

Trump has a "long history of racial discrimination," she said, adding he also trafficks in "dark conspiracy theories."

"He is reinforcing harmful stereotypes, and offering a dog whistle to his most hateful supporters as a disturbing preview of what kind of president he'd be," Clinton said.