It seemed bizarre. But Donald Trump’s choice last week of a renegade, far-right news executive to lead his campaign was an inevitable culmination of a candidate’s war with the mainstream media and his embrace of his party’s most incendiary voices.

Trump’s obsession with the media has been one of the few constants in his campaign. He rails against “scum” reporters, withholding credentials from major news organizations and lashing out on Twitter last week against the “failing New York Times,” while granting lengthy interviews to those same outlets and basking in their attention. He exploits the divide in conservative media to bash enemies and create safe zones on select TV and radio shows. He questions the core tenets of the First Amendment and flouts the judgment of fact-checkers with abandon.

The union of conservative media’s edgiest elements with the party’s standard-bearer has been years in the making, fomented by the establishment media’s loss of dominance and credibility. Trump, who has spent years learning how to navigate and dominate the news, has stepped into that credibility void to push once-fringe ideas into mainstream conversation like no other candidate.

“You have all these websites that create this echo chamber — that’s kind of an old term,” said Charlie Sykes, a conservative radio host in Wisconsin. “It’s gone beyond an echo chamber” to competing realities.

While trust in the media has fallen precipitously in the country, the drop among conservatives is especially large over the past two decades. Only about 1 in 4 Republicans surveyed by Gallup in 2014 said they trust the mass media, roughly half the level of trust expressed by Democrats.

Republicans have long fed off that trust gap, but Trump has made it a central talking point. “If the disgusting and corrupt media covered me honestly and didn’t put false meaning into the words I say, I would be beating Hillary by 20 percent,” Trump tweeted last week.

“The establishment media doesn’t cover what really matters in this country, or what’s really going on in people’s lives,” he said during a rally in North Carolina on Thursday.

Trump has used the distrust to join with sites like Breitbart in crafting what some observers see as an alternate reality where Trump is favored to win the election despite polls showing otherwise, where voter fraud is rampant in spite of evidence that it’s not and where stories that reveal darker aspects of Trump’s past are either examples of media bias or do not exist at all.

In tapping Stephen Bannon, editor of Breitbart News, as his campaign’s CEO, Trump has elevated a kindred spirit who, like Trump, relishes trafficking in taboo subjects and conspiracies once relegated to the far corners of conservative ­dialogue.

“Trump just hired a mirror,” said Ben Shapiro, a former editor at Breitbart who left in anger this year over what he saw as Bannon’s determination to create a “Trump media complex” at the expense of authentic conservatism. Shapiro has since criticized the site for promoting so-called alt-right voices who espouse white nationalism.

Breitbart and other sites have also helped bring rumors and conspiracies closer to the mainstream.

The latest rumor to reach Trump’s rhetoric: Clinton’s supposed failing health. In two speeches last week, Trump said she “lacks the strength and stamina” to fight terrorism. The comments alluded to unsubstantiated speculation on conservative websites, highlighted by Breitbart, that Clinton is too ill to serve as president.

Trump has capitalized on two decades in which conservative outlets have helped transform legitimate gripes with the media’s liberal slant into a “post-truth environment,” said Sykes.

Sykes pointed to Trump’s previous foray into politics — his promotion of the myth that President Obama was born outside the U.S., a persistent conspiracy theory that gained the label of birtherism.

“Now we have a Republican nominee who’s the nation’s premier birther,” said Sykes, whose tough interview with Trump was credited with diminishing Trump’s chances in Wisconsin’s spring primary, which he lost. “These things don’t happen in a vacuum.”

Sykes said that when he talks about news stories on his show that are critical of Trump, such as a Washington Post investigation showing Trump’s apparent lack of charitable donations, his listeners push back, asking why he would sell out by quoting the liberal media.

He said people who get news purely from Breitbart, the Drudge Report, Ann Coulter and the like were led to believe that House Speaker Paul Ryan was in serious danger of losing his primary to an outsider candidate who aligned himself with Trump. Ryan won with more than 80 percent of the vote.