Kelly's move from Fox News to NBC in 2017 was a risk for everyone involved.
Having built her personal brand on hard-hitting interviews and no-nonsense political commentary, she tried to shift into a very different role — hosting a 9am morning talk show.
The steely attitude that had worked so well for her on Fox was suddenly jarring.
"The experiment — having Kelly, who had been icily appealing on Fox News as a solo act, try to emulate Oprah Winfrey by playing warm and wise with a studio audience — moved quickly from misbegotten to miserable," CNN media analyst Bill Carter wrote this week.
"Ratings were tepid to worse, critical evaluation was scathing, internal dissension at NBC over the move was widespread."
Megyn Kelly Today replaced the third hour of NBC's existing morning show Today, and performed worse, losing hundreds of thousands of viewers.
It was quickly marred by controversy as well.
In her very first week on air, Kelly started a feud with actor Jane Fonda by asking her about her history of cosmetic surgery.
"It wasn't like I was upset. I was stunned. It was so inappropriate. It showed that she's not that good an interviewer," Fonda later told Variety.
Kelly fired back, saying the actor had "no business lecturing anyone on what qualifies as offensive" and pointing out Fonda had come on her show to "promote a film about ageing".
"The truth is, most older women look nothing like Fonda, who is now 80. And if Fonda really wants to have an honest discussion about older women's cultural face, then her plastic surgery is tough to ignore," Kelly said.
She said Fonda had discussed her cosmetic surgery extensively in the past and she could not have known "this subject was suddenly off limits".
Another actor, Will & Grace star Debra Messing, said she regretted going on Kelly's program after the host suggested a superfan she'd invited on stage had "become gay" because he was inspired by the show.
The proverbial final straw came last week, when Kelly discussed the contentious topic of people wearing blackface for Halloween.
"But what is racist?" she asked.
"Because you do get in trouble if you are a white person who puts on blackface on Halloween, or a black person who puts on whiteface for Halloween. Back when I was a kid that was OK, as long as you were dressing up like a character.
"There was a controversy on The Real Housewives of New York with Luann. She dressed as Diana Ross, and she made her skin look darker than it really is. And people said that was racist. And I don't know! I thought, like, who doesn't love Diana Ross? She wants to look like Diana Ross for one day, and I don't know how that got racist on Halloween."
There was a swift backlash from viewers who said Kelly had defended the use of blackface, and she quickly apologised on her program the next day.
"Sometimes I talk and sometimes I listen, and yesterday I learned," she said.
"I learned, given the history of blackface being used in awful ways by racists in this country, it is not OK for that to be part of any costume, Halloween or otherwise."
But it was too late.
When 9am arrived on Monday this week, Kelly wasn't there. Instead, the Today program simply continued into another hour, with three new anchors sitting at the desk.
"Today as you know, we are starting a new chapter in the third hour of our show as it evolves," one of them, Hoda Kotb, told viewers.
Megyn Kelly Today will never air again, and Kelly is on her way out of NBC with her reputation tarnished.
Making things even more awkward, Kelly and the network are reportedly struggling to reach an amicable exit deal, and it's unclear how much of that eye-popping $69 million she will actually receive.
Washington Post media columnist Margaret Sullivan told CNN the blackface blow-up was, in truth, only a "20 per cent factor" in Kelly's exit.
"Ratings weren't so good. She really never seemed to be the right fit for that job. She didn't have the warmth and the empathy and the personality to do that kind of morning show."
TRUMP'S NEMESIS
Few could have predicted Kelly's fall two years ago.
Her Fox News show was in a dominant position, fuelled by her uncompromising interviewing style and a willingness to occasionally stray from the staunchly conservative views espoused by the network's other evening hosts.
Her ratings even rivalled those of fellow Fox host Bill O'Reilly, whose show The O'Reilly Factor had remained unsurpassed for over a decade.
Kelly's fame surged when she moderated a Republican presidential debate and dared to confront Donald Trump with his long history of insulting women.
"You've called women you don't like fat pigs, dogs, slobs and disgusting animals," she said.
"Your Twitter account has several disparaging comments about women's looks. You once told a contestant on Celebrity Apprentice it would be a pretty picture to see her on her knees. Does that sound to you like the temperament of a man we should elect as president?"
Mr Trump was so incensed at Kelly's treatment of him that he feuded with her for months afterwards, labelling her a "lightweight" reporter, retweeting comments calling her a "bimbo", referring to her as "crazy Megyn", and infamously implying she had only asked that question because she was menstruating.
"I just don't respect her as a journalist," he said.
"I have no respect for her. I don't think she's very good, I think she's highly overrated.
"She gets out and she starts asking me all sorts of ridiculous questions, and you could see there was blood coming out of her eyes. Blood coming out of her wherever."
Megyn Kelly on the set of her NBC show Megyn Kelly Today. Photo / AP
Mr Trump boycotted another debate organised by Fox News after failing to get Kelly removed as a moderator. He also skipped a town hall forum she hosted, which every other candidate attended.
He continued to attack Kelly, labelling her "second rate", "unwatchable" and "biased". Eventually Fox News was forced to respond with an extraordinary public statement condemning Mr Trump's "sick obsession" with her.
"Donald Trump's vitriolic attacks against Megyn Kelly and his extreme, sick obsession with her are beneath the dignity of a presidential candidate who wants to occupy the highest office in the land," the network said.
"Megyn is an exemplary journalist and one of the leading anchors in America — we're extremely proud of her phenomenal work and continue to fully support her throughout every day of Trump's endless barrage of crude and sexist verbal assaults.
"As the mother of three young children, with a successful law career and the second-highest rated show in cable news, it's especially deplorable for her to be repeatedly abused just for doing her job."
Kelly was far tougher on Mr Trump than Fox's other evening hosts, such as Mr O'Reilly and Sean Hannity, who were consistently supportive of his candidacy.
That earned her plaudits elsewhere — but simultaneously alienated her from a chunk of the network's core audience.
After leaving for NBC, she told Ellen DeGeneres the spat with Mr Trump had contributed heavily to her decision.
"Donald Trump has a way of clarifying one's life choices," Kelly said.
"Just as I was sort of wondering if prime time news was where I wanted to be and how I wanted to live, the universe came and shone a light, and it was clear to me what I wanted to do.
"Bill O'Reilly, of all people, told me when I got to cable news prime time that cable news prime time is a snake pit. And that's how it felt, and I didn't want to be in the snake pit, I just wanted to cover the news."
Kelly now faces a tough dilemma. Her talents were perfect for prime time TV, even as she tried to escape it. Now that her attempted transformation has failed, will she return to what she does best?
