However, those Fox News viewers punch far above their weight in one regard: They are the core of any hard-right primary challenge that might be waged against an incumbent Republican senator. I believe based on conversations with knowledgeable Republicans that Trump is neither popular nor admired among the Senate majority, but he is feared, therefore tolerated. The fear stems from his firm grip on that Fox News-viewing core and the belief that he could turn the core into an incumbent-crushing machine.

To the extent that Trump’s grip begins to loosen, the fear will begin to lift and the president’s Senate firewall will begin to crumble. That’s how I figure it, and I think Trump might be making a similar calculation, because his Twitter feed has been peppered lately with his annoyance at Fox News over various perceived acts of hostility. He might believe that he can maintain his standing solely through his unmediated tweets, regardless of Fox News. But I don’t think he really wants to find out.

As it happens, Trump’s crisis finds Fox News at a turning point. With the sale of his company’s movie arm to Disney, founder Rupert Murdoch has cashed out a large part of his empire while anointing his eldest son, Lachlan, the chief executive of the media business. The death of Roger Ailes, accused sexual harasser and Fox News visionary, opens the way to fresh thinking – which the channel sorely needs, given its median audience age of about 65.