The media company was under extreme pressure from advertisers, protesters and its own employees ― all fed up with a company culture that enabled O'Reilly's misbehavior for too long.
But behind all that was the growing power of women, more emboldened than ever before, to protest sexual harassment and assault. For this, at least in part, we can thank President Donald Trump.
Trump's surprise victory in November sparked a massive wave of energy among progressives, activists and especially women, outraged that the reality TV star had won office despite more than a dozen sexual assault accusations, a record of strikingly misogynistic comments and insults, and a damning video in which he boasted of grabbing women by their genitals and kissing them without consent.
You'd think that Trump's election would have sent the message that speaking up doesn't matter. Instead, it galvanized an already growing movement.
"I never thought a man who openly bragged about committing sexual assault could get elected," said Karin Roland, chief campaigns officer for UltraViolet, a women's group that helped organize several anti-O'Reilly petitions and protests at Fox News headquarters in New York on Tuesday.
"Women are now trying to figure out how to make [sexual misconduct] something that would doom a future presidential candidate or aspiring athlete or a Fox News host," Roland said.
Pussy-gate was supposed to doom Trump. Last summer, after the tape of his bragging about grabbing women by the genitals was made public, thousands of women shared their own stories of sexual assault on Twitter and other social media. It was a natural next step. For at least the past couple of years, more and more women have been coming forward to tell their own stories of sexual assault and harassment.
Long-silenced women told horrifying stories about Bill Cosby in 2015, for example. Roland also pointed to the furor over Stanford student Brock Turner, who served just three months of a lenient six-month sentence for sexual assault last year. His victim bravely spoke up.
Trump's election only added fuel to the fire.
"Sometimes you have to take a step back to take two steps forward," said Amy Siskind, president of The New Agenda, a nonprofit women's group. She's been working on women's issues for close to a decade, after leaving a career on Wall Street. "There is a level of engagement and awakening now," she said. "I've never seen anything like it before."
The pressure on Fox News to dump O'Reilly began in earnest soon after a bombshell New York Times report on April 1 revealed that the network and the news host had together paid out $13 million to five different women who accused him of inappropriate behavior over a decade and a half. The women alleged that O'Reilly had targeted them with verbal abuse and lewd comments ― even phone calls in which he could apparently be heard masturbating.
Two of the O'Reilly settlements happened after Fox News Chairman and CEO Roger Ailes was ousted from the company. Female employees had accused Ailes of sexual misdeeds, including firing host Gretchen Carlson after she declined his sexual advances. At the time, Fox said it would no longer tolerate this kind of misconduct.
The New York Times story was a tipping point for advertisers, said Rashad Robinson, executive director of the racial justice nonprofit Color of Change. His group had been pressing companies to stop running ads on "The O'Reilly Factor" for two years, after reports emerged that the news host had lied about being attacked by protesters during riots in Los Angeles in the 1990s. Another group that got on Fox's case, Sleeping Giants, is actually a loosely organized group of volunteers who came together after Trump's win to push advertisers to abandon Breitbart News.
The Times story was hard for advertisers to ignore, Robinson said. As more of them pulled their spots from O'Reilly's show ― over 80 have dropped out ― the media ramped up its coverage, Robinson said.
Recently, Color of Change created a call line for Fox News employees to report harassment and placed ads online that geo-targeted social media users at Fox headquarters. Robinson hoped the ads were hard for Fox's human relations department to ignore. "We wanted to encourage employees to speak out," he said.
The ads look like this:
On Tuesday night, O'Reilly dismissed the idea that Americans were angry at him for good reason. In a statement, his lawyer said they had "uncovered evidence that the smear campaign is being orchestrated by far-left organizations bent on destroying O'Reilly for political and financial reasons." Yet to come: the promised "irrefutable evidence" of that.
But more Fox News employees and contributors have been talking, activists say. Earlier on Tuesday, a black woman who'd once worked at the network said O'Reilly had called her "hot chocolate" and made repeated comments about her appearance.
Adding to the pressure on Fox was Megyn Kelly's example: The rising star left the company in January in part because of O'Reilly's behavior.
"Women are fired up," Roland said.