Journalist Charles Blow schooled CNN’s Jeffrey Lord—and Donald Trump—after he defended the president’s praise of Andrew Jackson and assertion he ‘would never have let [the Civil War] happen.’

Trump made the claim originally in an interview with Salena Zito, telling the reporter, “had Andrew Jackson been a little bit later, you wouldn’t have had the Civil War.” He later dug his heels in on that claim, tweeting his predecessor “saw [the war] coming and was angry.”

Blow on Monday railed into the president’s Jackson praise, noting “the only acceptable resolution for the Civil War was the abolition of slavery.”

“What would Jackson’s compromise position have been?” Blow asked. “Some sort of semi-slavery?”

Lord tried to argue that “the Democratic party was build on the backs of slaves, and race,” prompting Blow to lay down a history lesson in the transformation of the Democratic party.

CNN’s Anderson Copper asked Lord how Jackson, “who owned hundreds of slaves,” could have “worked out” the Civil War.

“What appeals to President Trump is that he was tough as nails,” Lord replied, prompting Blow to explain what, exactly, “tough as nails” Jackson did as president.

“Andrew Jackson is also the person responsible for the Indian Removal program in the South that forcibly removed Indians from their lands and included the Trail of Tears when thousands of Indians died being marched West of the Mississippi,” Blow said. “This man was a white supremacist among white supremacists.”

“This is not the man who could have solved the slave issue in a way that would have been amenable to people who look like me,” he added.

“He doesn’t know anything about history, and refuses to read the history of the presidents that came before him,” Blow continued.

“This is what you get when you have a president who doesn’t read,” he added.

Watch the video below, via CNN: