Certainty has been the condition of the evening programs on Fox News for a generation, but on Tucker Carlson’s show on Wednesday night, which aired just a few hours after the Justice Department announced it had appointed a special counsel to oversee the investigation of possible links between Donald Trump’s Presidential campaign and Russia, doubt crept onto the screen. Kellyanne Conway, Trump’s counsellor, had been scheduled to appear on the show, Carlson told his audience, but the White House had cancelled shortly before broadcast, without giving much of an explanation. “It does seem a little chaotic over there,” Carlson observed. To replace Conway, he had invited Matthew Schlapp, the President of the American Conservative Union and a Trump ally, who had been to the White House earlier in the day, and who said the atmosphere there had been tense. “There really is nothing more stressful in life than being investigated,” Schlapp said. Carlson agreed.

On Tuesday night’s program, Carlson had gleefully admonished a Democratic guest, the New York City councilman Corey Johnson, to get the bathrooms in Penn Station cleaned up (“It’s disgusting!”) before he would entertain the notion of a special prosecutor. A day later, the bathrooms in Penn Station were in much the same condition but the nation had a special counsel: the former F.B.I. director Robert Mueller. Carlson’s tone was very different. He said he still thought that a special prosecutor was a bad idea, but he assured his audience that Mueller was “an adult,” and “about as impressive a choice as the Justice Department could have made.” He mentioned the Bronze Star that Mueller earned for leading a detachment of infantrymen in Vietnam. Carlson is still new to the eight-o’clock show—he took over the hour last month, after Bill O’Reilly’s sudden departure from the network. In Carlson’s vacillations over the past two nights, between cocksure partisanship and deference to Mueller’s institutional authority, it seemed as if he were groping, trying to figure out where his audience was, and what it was willing to hear.

For two decades, the chief facilitator of this relationship, between conservatism in all its different shades and the Fox News audience, was Roger Ailes, the longtime network chief and onetime Nixon media consultant, who died on Thursday morning, at the age of seventy-seven. Ailes was ousted in July, after a lawsuit brought by Gretchen Carlson, a Fox News host who accused Ailes of sabotaging her career after she refused to sleep with him, was followed by allegations by several other women that Ailes had sexually harassed them, too. Ailes held deep convictions about what his audience wanted, and these were, for years, most precisely projected on the air by the smug, exasperated O’Reilly, who had the same sure hand for his audience that Mike Francesa does for the New York sports fan, knowing when to let gripes about the Mets bullpen run, and when to pivot, just to break things up, to the Knicks’ errors in the draft. But now both Ailes and O’Reilly are gone, chased by separate sexual-harassment lawsuits, and to watch Tucker Carlson is to feel their absence. It seemed a mark of how alienated the old Fox News is from the current one that Ailes’s wife sent the news about her husband’s passing not to the network he had led for twenty years but to Matt Drudge, the conservative Internet hero.

Republican politicians must feel this absence especially. For all the ideological chaos within the Party’s base, its careening between libertarianism and nationalism and a fading virtuous conservatism, Fox News has long been a reliable guide. A Republican elected official trying to figure out what his constituents wanted to hear could simply reflect what was being said on Fox. To know how he was doing, that same elected official needed only to listen to how the network’s anchors spoke about him. There have been a number of fringe Republican Presidential candidates over the years who have seemed mostly to compete for airtime on the network. In Fox's complicated relationship with the Trump phenomenon, you could trace the mainstream conservative’s own journey—at first basically disapproving, then moved by instinctual partisanship, before settling on a shared antagonism toward liberals. Trump pushed the buttons; Ailes and O’Reilly showed him where they were.

One of the most pressing questions in American politics today is whether the conservative support for Trump will fracture. Carlson, in introducing Mueller as a character on Wednesday night, inadvertently demonstrated what a complicated contrast the former F.B.I. director makes with Trump. Mueller and Trump are both white men in their seventies, but the lawman was a war hero while the President was a draft dodger. The loyalty to Trump is partisan, while the loyalty to Mueller is institutional. Behind one man, a celebrity, there is a cult of personality; behind the other, a bureaucrat, there is a cult of rectitude. It is as if the Fox News aesthetic has been cleaved neatly in half. Republican politicians, wondering now how far to move from Trump, are watching their voters, who are watching Carlson, who is watching the two principals, Mueller and Trump. Without Ailes to arrange the frame, each gaze in that sequence is complicated by a new uncertainty. Who to trust?