New York, New York - Donald Trump has been aggressively attacking his rival Kamala Harris' intelligence throughout the presidential race, but comments reportedly made at a private dinner take the rhetoric to a new level.

According to The New York Times, the presidential candidate held an event for major Republican donors at his Manhattan penthouse apartment in Trump Tower on September 29.

The 78-year-old, who was frustrated about Harris outperforming him with campaign fundraising, reportedly told donors they needed to "do more, appreciate him more, and help him more," while boasting that he gave wealthy people tax breaks when he was president.

At one point, Trump reportedly referred to the VP as "retarded," and complained that Jewish voters supporting her "needed their heads examined."

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The Times reported that Trump's anger stemmed from Harris having raised more money in her three months as the Democratic candidate than he has raised in the entire year.

That anger has been manifesting as increasingly vicious attacks on Harris' intelligence, and sometimes her gender, particularly behind closed doors.

In a similar report from the Times back in August, sources close to his campaign claimed they had heard Trump "repeatedly" call Harris a "b****."

In response to the recent report, the Trump campaign didn't address his comments, instead claiming that he's "in a better financial position than ever before, and he's leading in the polls."