Former New York Mayor Rudy Giuliani blamed Barack Obama — the nation's first Black president — for a deterioration of race relations in the United States.

On his Sunday radio program, Giuliani called Democrats "the party of slavery."

"These miserable anti-American leaders of the party of slavery have taken us back 40 or 50 years on race relations with Obama," he said. "It began with Obama."

"Before that, I mean, they — every — Republicans are racist. I mean, they love John McCain until he became the candidate of the Republicans, then he was crazy, insane; something happened to him during the war; he's a racist. Bush was called a racist all the time."

Giuliani noted that Donald Trump was also often called a racist.

"Trump gets into I think a psychological illness they have about Trump," he said. "Trump derangement syndrome is real — so obsessive."

Giuliani argued the problem of race relations "has been building for quite some time."

"You think it's accidental; I know it's Marxist planned and executed over a long period," he claimed. "Open border is not coincidental. The open border comes right out of Karl Marx. It comes right out of [communist activist] Saul Alinsky, who, by the way, Saul Alinsky and his acolytes taught Barack Obama and Hillary Clinton."