It’s not like the aggressive Fox questioning should have been a surprise. In the days leading up to the debate, Trump’s advisers expected Fox to be tough, especially Kelly, whom Trump has tangled with in the past. Earlier this week I reported that Trump’s friend Rudy Giuliani reached out to Ailes to ask that Kelly be fair to Trump. (Giuliani denied this.) In a phone call with a friend the other day, Trump grumbled about Fox’s on-air treatment of him. But even Trump’s campaign was taken aback by the intensity of the debate questions. Campaign lawyer Michael Cohen tweeted that it was a “total setup” designed to “lower #Trump2016 high poll numbers.” Another Trump adviser told me that the debate was “vicious” and a “hit job.”

It’s unclear what, ultimately, convinced Ailes to let his moderators go after Trump. He may have wanted to shoot first to prevent Trump from damaging Fox in a live situation, as they say in the business. Perhaps Murdoch got to Ailes. Or, perhaps, Ailes just wanted good television. (Fox did not respond to a request for comment.)

For Trump, whether this is a flesh wound or something deeper is also unclear. He’s surged to the top of the polls by winning every fight he’s picked so far. But for Trump’s troubled campaign, Ailes could prove to be a tougher opponent than any he’s faced. After all, no other candidate controls the television network that reaches the biggest block of primary voters. Those are the kind of poll numbers that are tough to beat.