Roger Ailes is arguably the most powerful person in cable news — a position he seems on the verge of being booted out of.

Ailes, now 76, built the Fox News Channel from the ground up, becoming an almost singular force in both the cable news business and Republican politics in the process. After two decades of operation, Fox News brings in $1 billion a year in profit, accounting for 18 percent of all of 21st Century Fox's profits in 2014. Wall Street puts the channel's value at $15 billion. While its viewership has declined from its peak early in the Obama era — something like one in four Americans got their news from Fox in 2010 — it still dominates competitors like CNN and MSNBC by enormous margins.

As Fox News' chairman and CEO, Roger Ailes oversaw all of that. It often seemed that nothing could bring him down.

Then on July 6, Gretchen Carlson — a former Fox News host — upended Ailes' career by suing him for a long string of alleged sexual harassment, unwanted advances, derogatory comments, and workplace retaliation. Six more women have publicly accused Ailes of sexual harassment since, and several anonymous Fox employees told various outlets that they were victims as well. Ailes has vehemently denied any and all allegations.

While Fox News is saying nothing definitive, the network is reportedly in talks with Ailes that are widely expected to end with him relinquishing his crown as head of the channel.

Ailes' run at Fox News has been characterized by, shall we say, a strong and centralized style. "Every aspect of the organization reported to him," one TV news executive told CNNMoney. "He held the place together. He's the only person who's ever run it." Ailes learned early not to trust anyone but himself; he says his father once convinced him to jump off a bunk bed, and then purposefully didn't catch him.

All roads at Fox News appear to lead back to Ailes. Several of the network's biggest stars — Bill O'Reilly, Sean Hannity, and Great Van Susteren, for example — all reportedly have clauses in their contracts allowing them to leave early if Ailes himself departs, testifying to the degree to which Ailes' leadership has shaped Fox News.

That has sometimes won him the intense loyalty of his employees. But it also means that Ailes and Ailes alone is who anyone looking to change Fox News needs to go through. He received a demotion of sorts in 2015, when Rupert Murdoch began the process of stepping down as CEO of 21st Century Fox. So Ailes now reports to Murdoch's two sons — James and Lachlan — rather than to Murdoch directly. The younger Murdochs have made no secret of their desire to update Fox News, and Ailes' feuds with them are legendary. And yet, his contract was recently renewed for several more years.

There appears to be no obvious replacement for Ailes. One name floated by CNNMoney's sources is Bill Shine, the senior executive vice president of programing who runs Fox News' primetime content. But no one seems terribly enthusiastic about any particular candidate's ability to recreate Ailes' magic.

Ailes began work as a small-time TV producer in Cleveland, then as the TV producer for the Nixon campaign, then came to New York City, where he spent time as a talent agent and an Off Broadway producer, among other things. In the 1990s, he produced Rush Limbaugh's television show. He co-wrote a book called You Are the Message.

During his two decades at Fox, Ailes has played a key role in multiple presidential runs and wields enormous influence in GOP politics. But as Jill Lepore mused in 2014, it might be a mistake to view Ailes as a political creature:

In 1972, [Ailes] helped run the North Carolina gubernatorial campaign of Jim Holshouser, Jr., a Republican who supported busing. "If you don't do an antibusing spot on TV, you will lose the election," Ailes told Holshouser. "Now, if I were you, I'd do the f--king spot, win the election, and then, once you're in office, do whatever you think is right." Holshouser did the spot and won. ("And what did he do about busing?" [Ailes' biographer Zev Chafets] asks Ailes. Ailes answers, "I have no idea.") [The New Yorker]

In other words, it's not about principles. It's saying and doing what it takes to win. And in the world of cable news, it's that Ailes-concocted hybrid of conservative politics and entertainment that has helped Fox win.

There's an argument that Ailes' alchemical transformation of politics into entertainment actually helped undo his own party: "Between 1952 and 1988, an era marked by the Fairness Doctrine (and, according to conservatives, a liberal media), Republicans won seven out of 10 presidential elections," Lepore observed. "Between 1988 and 2012, during the ascendancy of conservative media, Republicans won only three out of seven presidential elections."

But more deeply, it means entertainment and its demands are the forces that ultimately rule Ailes' fate.

Fox News' biggest star today is far and away Megyn Kelly, reportedly the most highly sought talent in television news, able to command a salary of $15 million to $20 million. Kelly herself has been mum on the news of Carlson's lawsuit. But sources told New York that Kelly was the victim of Ailes' harassment about 10 years ago, that she described the unwanted sexual advances to Fox News' investigators in detail, and that she encouraged other female Fox employees Ailes allegedly harassed to speak out. One executive told CNNMoney that to keep Kelly Fox News would "need to convince her that she would be the face of the network going forward, and that it would abandon its image as the network of old, white, conservative men."

The problem with staking all your power on being an entertainer, it seems, is that eventually someone becomes a bigger entertainer than you.