It’s possible that the audience for wisenheimer TV has grown large enough to support whatever experiment Colbert has in mind. These shows are less dependent on the number of people who make a bedtime viewing appointment and more on sketches that are striking or lucky enough to get passed around online. The prestige-television trend has also groomed audiences to work harder for television than, in some cases, it works for them — committing to years-long story arcs, pondering complex characters, deciphering oblique plots and open endings, and so on. It’s bewildering to this reviewer, for whom “quality television” means any show where the theme song explains the premise of the show. But the media environment is vast enough to support both hedgehogs and foxes.

There may be a political element as well. Rush Limbaugh’s claim that CBS “declared war on the heartland of America” with the Colbert pick seems overly broad, but it’s not entirely made up. Colbert’s sister was the Democratic challenger to Mark Sanford in last year’s special election for South Carolina’s First District congressional seat. He’s made his career appealing to blue-state hipsters by ridiculing Fox News. And it’s not like the playing field was free of politics to begin with: Common sense suggests the fact that Leno was truly a free agent in his political humor at least partly informed NBC’s decade-long determination to get rid of him while he remained at the top of his game.

But the distinction still seems more a matter of temperament than of politics. The parties are Leno and Letterman more than Republicans and Democrats. And again, the kinder, gentler approach seems to be the winner: Fallon has been killing it in the ratings, even in the week Letterman announced his retirement.