Since the election, numerous congressional Republicans have refused to publicly weigh in on any Trump proposal at odds with Republican orthodoxy, from his border wall to his massive infrastructure package. The most common reason, stated repeatedly but always privately: They’re afraid of being attacked by Breitbart or other big-name Trump supporters.

“Nobody wants to go first,” said Rep. Mark Sanford (R-S.C.), who received nasty phone calls, letters and tweets after he penned an August op-ed in The New York Times, calling on Trump to release his tax returns. “People are naturally reticent to be the first out of the block for fear of Sean Hannity, for fear of Breitbart, for fear of local folks.”

An editor at Breitbart, formerly run by senior Trump adviser Steve Bannon, said that fear is well-founded.