Back in September, just before CNN chairman and C.E.O. Chris Licht formally announced that he’d be giving Jake Tapper a trial run in primetime, a high-level CNN source sought to assure me that Licht had other tricks up his sleeve if the Tapper experiment didn’t pan out. Licht certainly hoped Tapper would become the permanent anchor at 9 p.m., a marquee hour that had been effectively vacant since Licht took over the network in May. But he was also aware that Tapper had reservations about primetime, and that his professorial disposition might not prove to be a natural fit for cable’s more personality-driven hours—as would indeed turn out to be the case.