But the chronic troubles of prime-time remain. Sometime before the network “upfront” events in April, when advertisers buy commercial time for the fall season, Mr. Zucker needs to signal how he will fix CNN’s prime-time problem, and that begins with Mr. Morgan, whose contract ends in September.

Mr. Morgan has some significant skills that do translate across platforms and cultures. While working as a newspaper editor and television personality in Britain, he was involved in a number of controversies, but he developed a reputation as a talented, probing interviewer. In his current role, he has shown an ability not only to book big guests — former President Bill Clinton, Warren Buffett, the real Wolf of Wall Street among them — but also to dig in once they are on set.

“I think I can credibly do news and the ratings reflect that, but it is not really the show that I set out to do,” he told me. “There are all kinds of people who can do news here. I’d like to do work — interviews with big celebrities and powerful people — that is better suited to what I do well and fit with what Jeff is trying to do with the network.”

Old hands in the television news business suggest that there are two things a presenter cannot have: an accent or a beard. Mr. Morgan is clean shaven and handsome enough, but there are tells in his speech — the way he says the president’s name for one thing (Ob-AA-ma) — that suggest that he is not from around here.

There are other tells as well. On Friday morning, criticizing the decision to dismiss a cricket player, he tweeted, “I’m sure @StuartBroad8 is right and KP’s sacking will ‘improve performance’ of the England team. Look forward to seeing this at T20 WC.” Mr. Morgan might want to lay off the steady cricket references if he is worried about his credibility with American audiences. (His endless trolling of his critics on Twitter did not exactly help, either.)

People might point to Simon Cowell as a man with an accent and a penchant for slashing discourse that Americans loved, but Mr. Cowell is dealing with less-than-spontaneous musical performances, not signal events in the American news narrative. There was, of course, the counterexample of David Frost, who did important work in news, but Mr. Frost did popular special reports and was not a chronic presence in American living rooms.

Mr. Morgan, who was chosen in spite of that fact that he had never done a live show, had the misfortune of sliding into the loafers of Mr. King, who, for all his limitations, was a decent and reliable stand-in for the average Joe.