Controversial TV host Tucker Carlson on Wednesdsay claimed Dr Jill Biden is "borderline illiterate" during a rant on his Fox News show.
Mr Carlson suggested the incoming first lady "can't think clearly" as he launched a scathing attack on her doctoral thesis.
His comments came just days after a row broke out over a "sexist" column published in the Wall Street Journal, which suggested Dr Biden should remove the "Dr" from her name because she is not a medic.
On his Wednesday night show, Mr Carlson reviewed a thesis written by Dr Biden for a doctoral degree in education, which she completed at Delaware University in 2007.
Mr Carlson said the paper contained a host of typos and errors, describing it as "our national shame".
He pointed out the dissertation's numerical inconsistencies and said parts "seem to be written in a foreign language in English words" and are “pure nonsense".
He added: "The whole thing is just incredibly embarrassing and not simply to poor, illiterate Jill Biden, but to the college that considered this crap scholarship, embarrassing in fact to our entire system of higher education, to the nation itself."
Mr Carlson, who has amassed a huge following with his outspoken views, went on to claim that criticising Dr Biden would be classed as sexism or misogyny.
“Whatever you do, do not make fun of it," he said. "If you dare to notice that Dr Jill isn't a supergenius, you hate all women. You're a dangerous misogynist.”
He also argued that the incoming first lady and others use "fake" credentials to "justify their power over you."
Mr Carlson's Wednesday night rant was the second time this week he attacked Dr Biden's qualifications.
On Monday, he condemned Dr Biden for using the title because she is "not a doctor" except "maybe in the same sense Dr Pepper is".
Monday's remarks came in response to the WSJ opinion piece published over the weekend and penned by the writer, essayist and former editor of The American Scholar, Joseph Epstein.
In it, Mr Esptein, 83, referred to Dr Biden, 69, as "kiddo", before going on to suggest that she should drop the "Dr" in front of her name because she does not have a medical background.
Elizabeth Alexander, communications director for the future first lady, described the piece as "sexist and shameful".
Michael LaRosa, Dr Biden’s transition team spokesman said the WSJ "should be embarrassed to print the disgusting and sexist attack".
The incoming first lady responded to the attack with a simple, coded message.
She wrote on Twitter: "Together, we will build a world where the accomplishments of our daughters will be celebrated, rather than diminished."
The WSJ's opinion page editor on Sunday defended the article, saying criticism of it was "overwrought" while accusing Dr Biden's team of politicising what is a "relatively minor issue".
