"Breitbart News is no longer a journalistic enterprise, but instead, in my opinion, something resembling an unaffiliated media Super PAC for the Trump campaign," Schachtel said in a statement first reported by Politico. "I signed my contract to work as a journalist, not as a member of the Donald J. Trump for President media network."
I resigned from Breitbart. Was a great run & I wish I could've prevented what it's become. Still many grt ppl there. Sorry to let u all down
Fields accused Trump campaign manager Corey Lewandowski of grabbing her arm so hard she bruised as she attempted to question the candidate at an event. She wrote an account of the incident, as did a Washington Post reporter who said he witnessed it. Politico also published an audio transcript that purportedly captures the interaction and moments immediately afterward.
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The Trump campaign fought back hard against the allegations. Lewandowski called Fields "delusional" and an "attention seeker," while Trump accused the reporter of having "made up" the incident. Fields, meanwhile, filed a police report.
In the immediate aftermath, another Breitbart reporter appeared to question Fields' allegations on Twitter. That reporter was suspended — and the news site's chief executive issued a statement backing Fields and calling on Lewandowski to apologize.
However, the site then published images questioning whether the Washington Post's Ben Terris misidentified Lewandowski as the person who may have physically assaulted Fields. Breitbart later published a piece purporting to show text messages from Lewandowski which it said "prove" he didn't assault Fields.
Her colleague Shapiro went further, accusing Breitbart of abandoning and undercutting Fields in order to protect a "bully" — Trump — and his "bully campaign manager."
"Both Lewandowski and Trump maligned Michelle in the most repulsive fashion. Meanwhile, Breitbart News not only stood by and did nothing outside of tepidly asking for an apology, they then attempted to abandon Michelle by silencing staff from tweeting or talking about the issue," Shapiro said in a statement issued to Buzzfeed.
He said the story suggesting Fields and Terris had misidentified Lewandowski — a "poorly-evidenced conspiracy theory" — was the "ultimate indignity."
"This is disgusting," Shapiro said. "No news outlet would stand for it."
Breitbart News has not formally commented on the resignations.
Breitbart later posted a statement in its place from editor-at-large and in-house counsel Joel Pollak who apologized to Fields and Shapiro for the piece.
"The article was written by me as part of an effort to make light of a significant company event, and was published as a result of a misunderstanding without going through the normal editorial channels," the statement said.
Those issues were amplified in recent days after video emerged of a man at a Trump rally sucker-punching a protester leaving an event in North Carolina and fights broke out at a cancelled event in Chicago.
Cassandra Vinograd is a Senior Writer and News Editor. Before joining NBC News, she worked as a London-based correspondent for The Associated Press and specialized in politics, foreign affairs and defense.
Vinograd previously worked as an editor for The Wall Street Journal in Brussels and London.
She has reported extensively from Afghanistan and on West Africa and the Middle East.
Shamar Walters, Anna Brand and Jon Schuppe contributed.