Sean Hannity of Fox News arrives on stage to speak at the Conservative Political Action Conference in March 2016 in National Harbor, Md. (Carolyn Kaster/AP)
Brian Rosenwald is a senior fellow at the Fox Leadership Program at the University of Pennsylvania and one of the co-editors of Made by History. He is working on a book on the rise of talk radio and its political and policy impact between 1988 and 2016.

It shouldn’t surprise us that Sean Hannity is serving almost as an unofficial chief of staff for President Trump. In fact, it’s fitting. After all, conservative media is responsible for Trump’s rise.

For more than a quarter-century, talk radio and cable news fed a desire among conservative voters for unyielding pugilists who would champion their traditional values on issues ranging from gender roles to sexual behavior to race — and who, most importantly, punched back at political correctness. These media also ran down mainstream journalists, eroding their credibility among conservatives. And they fused news and entertainment into infotainment, a product more concerned with keeping the audience tuned in than factual accuracy.

All of this created an opening for a presidential candidate like Trump. He finally gave these conservative voters the sort of champion at the ballot box that they had long had on the airwaves. The power of conservative media also explains the durability of Trump’s popularity among supporters, despite his ethical foibles and boorish behavior. Conservative media outlets, which have constantly harped on how biased journalists are against Trump, have transformed stories about Trump’s transgressions into stories of media malfeasance. In doing so, hosts like Hannity have not only made Trump’s presidency possible, they have also made it sustainable. And they have made it far more likely that even after Trump, his style of politics will endure.

First things first: Conservative media is not part of the news business. It exists to entertain and make money. Rush Limbaugh, the king of conservative media, has made this clear: “I don’t deny I’m an entertainer; this is showbiz,” he told his audience in 2015. “But I also don’t deny that I am deadly serious about the things I care about. And I definitely want certain things, ideas, to triumph, and others to lose, big time.”

Debuting nationally in 1988, Limbaugh pioneered a unique media product that applied the skills and shtick he had developed as a disc jockey to make conservatism exciting and accessible. Instead of the fact-based reporting then offered by the mainstream media or the serious political commentary supplied by conservative publications like National Review, Limbaugh provided unabashedly conservative takes on the news, conveyed in a fun, zany, controversial way.

While other conservatives offered intellectual analyses or strident lectures about the evils of communism, for example, Limbaugh playfully discussed liberal “Gorbasms” — “the expression of sheer delight that [Soviet leader Mikhail] Gorbachev was on the scene” — to run down those who lionized Gorbachev while scorning Ronald Reagan as a warmonger.

Some of his antics were highly controversial — like the caller abortions in which Limbaugh drowned out liberal callers by playing a vacuum cleaner sound effect and screams. But this controversy helped Limbaugh’s show become a smash hit. By 1993, it aired on 610 stations and had 17 million listeners per week. Limbaugh’s success shaped a new media format that took over AM radio and spread to cable television when Fox News debuted in 1996.

Unlike journalists, for whom the biggest sin was getting facts wrong, for Limbaugh and his colleagues, the only sin was boring the audience.

And nothing resonated with their audiences quite like their assault on the rights movements of the 1960s and 1970s. Conservatives took particular umbrage with the way civil rights and feminism successfully brought ideas of gender equality and diversity into mainstream conversations — including in the media. Journalists increasingly reflected a cultural liberalism that threatened the traditional values that conservative media’s audience considered to be responsible for American greatness. When conservatives dared to challenge the new norms, they were branded racist or sexist. Rightly or wrongly, they felt bullied into silence by a liberal establishment composed of the Democratic Party, Hollywood, the mainstream media and academia.

Enter Limbaugh, who was proudly politically incorrect. He reveled in his sexism, joking that he supported the women’s movement, especially when walking behind it. He recounted tales like that of an all-male club that was forced to admit women, who then demanded a women’s exercise room. Limbaugh gleefully shared the punchline: The club responded by providing one with “exercise equipment” — a washer, an ironing board and a vacuum.

These same tactics shaped Fox News as it grew the market for conservative “infotainment.” As one fan of former Fox News star Bill O’Reilly told scholars Jeffrey Berry and Sarah Sobieraj, “I just think he’s obnoxious. I guess I wish I could be obnoxious like that sometimes. … In your day-to-day interactions at least, you sort of have to be polite and every once in a while you’d like to just say what you really think. And these guys do.”

Hosts delighted these fans every day by punching back against those who set the new bounds of propriety. They provoked, as retired talk radio star Neal Boortz termed them, “the howling dogs of the left-wing media” by saying things “that many people were thinking, but were afraid to express.”

Initially these tactics were confined to the realm of talk radio and cable news. Even as conservative Republicans gained political power, they didn’t offer the bluntness and hyperbole of O’Reilly or Limbaugh. After all, they needed to win elections and then actually govern, so they couldn’t always adopt unyielding and politically incorrect positions. The reality of compromises and pulled punches, however, felt like selling out to hosts and audiences. It fueled the outrage on the airwaves and television screens — especially because nuanced explanations of these actions made for rotten programming.

Soon, talk radio and cable news were doing more than deriding moderates as RINOS (Republicans in Name Only). As the party grew more conservative, the label was extended to party leaders and conservatives who refused to champion hard-line tactics like forcing government shutdowns to achieve unrelated policy objectives.

As hard as conservative hosts were on impure Republicans, they were even harder on the mainstream media. Hosts relentlessly slammed mainstream journalists for what they perceived as subtle attempts at boosting Democrats and delegitimizing conservatives. Limbaugh trotted out the nickname the “drive-by media,” inviting thoughts of violent drive-by shootings — in this case against victims like truth, fairness and objectivity.

All this — the crass insults, the anti-PC politics, the insistence on extremism, the attacks on the media — paved the way for a Trump presidency.

While Trump doesn’t always subscribe to hosts’ preferred ideological purity, his combative style is ripped straight from the playbook of conservative media. His caustic tweets toward everyone from Democratic leaders to mainstream journalists reflect the seething anger felt by disgruntled hosts, listeners and viewers who feel belittled by the liberal establishment — as do his derisive nicknames like Cryin’ Chuck and Crooked Hillary. He also relentlessly pounds what he has dubbed the “fake news media.”

Most of all, like the best hosts, Trump puts on a good show. No one knows what to expect from him from day-to-day, and nuance has no place in his White House.

And, especially given that members of the conservative media have regularly talked with Republican leaders, both on their shows and behind closed doors, for years, it is no surprise that Hannity — who speaks the president’s language and reinforces his instincts to be himself and punch back against political opponents — is one of Trump’s closest advisers.

Before the rise of talk radio and Fox News, the notion of a brawler of a president who hurls insults at everyone and listens more to media personalities than American intelligence agencies would have been inconceivable. But conservative media changed the political game by creating an audience hungry for exactly this type of politician. Along the way, they destroyed the best potential check on this sort of behavior: Americans of all political stripes trusting journalists who alerted them to politicians’ misdeeds.

It’s a precedent with consequences that will outlast the Trump era. So long as conservative media retains its place of primacy within the GOP, Americans have to brace themselves for the high probability that Trump is not an outlier, but the new model for successful Republican politicians.