"Celebrity is everything in this country," Breitbart said in an appearance on Fox News, calling Trump "not a conservative."
Breitbart, who launched an irreverent, anti-establishment conservative news site that shares his name, said then that Trump's media savvy and his plans for a presidential run should be a warning to the Republican establishment. "If these guys don't learn how to play the media ... we're going to probably get a celebrity candidate."
Breitbart, who died in 2012, was right: Trump has become that celebrity candidate who threatens to redefine conservatism itself. Ignoring establishment orthodoxy, Trump has gained endless TV attention and overpowered establishment opponents, which has threatened to start a civil war over the future of the Republican Party.
But Breitbart did not foresee that the political tensions unleashed within the GOP by Trump's candidacy would consume his own conservative media empire.
It began last week when a Breitbart reporter accused Trump's campaign manager of violently grabbing her, which led to the resignations of several staffers who publicly denounced the company on the way out the door. They said that Breitbart had surrendered its editorial independence and become a mouthpiece for Trump, to the point that it valued protecting Trump's campaign more than standing behind one of its journalists.
Breitbart's chairman, Steve Bannon, has turned the site "into Trump's personal Pravda," editor at large Ben Shapiro, who is based in Los Angeles, said in a statement on his resignation. "Andrew built his life and his career on one mission: fight the bullies. In my opinion, Steve Bannon is a bully, and has sold out Andrew's mission in order to back another bully, Donald Trump." Bannon couldn't be reached for comment.
"Some of us have been fighting behind the scenes against the party-line Trump propaganda for some time, but without any success, unfortunately," one reporter, Jordan Schachtel, said in a statement after resigning Monday. "Breitbart News is no longer a journalistic enterprise, but instead, in my opinion, something resembling an unaffiliated media Super PAC for the Trump campaign."
Inside the company, some employees deny being beholden to Trump, saying the site is being criticized for trying to cover him neutrally. Some have also maintained that the arm-grabbing incident was overblown and that the confusion that followed was the result of poor communication.
Fallouts aren't uncommon at media outlets, especially when big personalities are involved. But sources around the company say the rupture at Breitbart was unique in the recent history of conservative media, and that the conflict reflects greater upheaval within the Republican Party.
"In a lot of ways, the story of Breitbart is a manifestation of what's happened in the 2016 primary," said former Breitbart.com spokesman Kurt Bardella, who resigned and accused the company of dishonesty. "I don't think I've ever seen anything quite like what's happened in the past week with any media entity before."
As Trump has battled criticism from conservative voices at Fox News, the Wall Street Journal and the National Review in recent months, Breitbart.com has been perceived by conservatives as one of Trump's most vocal supporters — as well as a notably harsh critic of Trump's opponents.
"What's so unusual about Breitbart is it became completely indistinguishable from the Trump campaign," said Eric Boehlert, a senior fellow at the liberal media watchdog Media Matters. Trump's platform "is freaking out so much of the conservative press, because they don't recognize this, they don't agree with this agenda, and they're just horrified that this Frankenstein is now marauding the countryside with this pitchfork-wielding crowd in pursuit."
Breitbart.com has touted Trump as a "populist nationalist" conservative for his hard-line stances on immigration, trade protectionism and national security. When Trump said fellow candidate Ted Cruz couldn't become president because he was born in Canada, Breitbart.com ran dozens of stories on the issue.
Some attacks have been especially harsh. One recent column by Milo Yiannopoulos labeled then-candidate Marco Rubio "Narco Marco," saying with no real evidence that he was taking ADHD medication.
The site has been widely criticized by other conservatives, who call it "Trumpbart." When one Breitbart reporter accused Republican consultant Frank Luntz of being biased in Rubio's favor, Luntz told the reporter, "You are so far up Trump's ...."
"Bad words… But I was right," Luntz tweeted Wednesday.
Tensions inside the company broke into the open when Breitbart reporter Michelle Fields accused Trump campaign manager Corey Lewandowski of yanking and bruising her arm as she tried to interview Trump at a crowded event on March 8.
Fields, who filed a misdemeanor battery charge, went on Twitter and made media appearances to talk about the incident, and wrote in an essay on Breitbart.com, "I never sought to become part of the story."
Larry Solov, Breitbart News' chief executive and president, initially backed Fields and said, "It's obviously unacceptable that someone crossed a line and made physical contact with our reporter." He asked Lewandowski to make "an immediate apology" if he was the one who had grabbed Fields.
Lewandowski didn't apologize. On Twitter, he called Fields "delusional" and said, "I never touched you." Trump also called the allegation "entirely false," and a campaign spokeswoman said in an interview this week that Lewandowski "did nothing wrong."
Then Breitbart undercut Fields, when Santa Monica-based editor Joel Pollak published a post suggesting a different man may have grabbed her — only to backtrack when footage emerged that appeared to show Lewandowski reaching for Fields. Pollak declined to comment for this story.
Breitbart's Washington political editor, Matthew Boyle, who covers Trump, published his own text exchange with Lewandowski from the night of the incident.
"It sounds to me like it was a misunderstanding nothing bad," Boyle texted to Lewandowski, who responded that he didn't know who Fields was. Boyle added: "I wanna make sure that this doesn't turn into a big story. It sounds to me like it was a misunderstanding."
Fields soon resigned, along with Shapiro and at least three other employees. Fields also declined to comment, saying, "Breitbart has sent me legal documents preventing me from speaking about this."
The players have now gone mostly quiet, but the incident seems to have become yet another polarizing campaign issue among conservatives: How you felt about the controversy at Breitbart, reporter Lee Stranahan tweeted, was like "a Rorschach test on how you feel about Donald Trump."