Donald Trump Jr. slammed Vice President Kamala Harris as a "phony moron" after his father backed out of an ABC News debate that he had previously agreed to attend.

In a Sunday afternoon post on X, the former president's son amplified a message from Republican vice presidential nominee J.D. Vance.

"It's been 14 days since Kamala Harris became the presumptive nominee of the Democrat Party and she still hasn't sat for a single interview with the media," Vance wrote on Sunday.

"Last time the press allowed a Dem to run a campaign from their basement, we ended up with brain-dead Joe Biden as Pesident," Trump said in response to Vance's message. "Now they're trying to stick us with his apprentice: A phony moron who can't complete a full sentence without someone telling her what to say."

Hours earlier, Trump complained about "projection" from Democrats.

"Has there ever been a bigger case of projection in history than Kamala Harris calling someone 'weird?'" he remarked in defense of Vance.