Here’s the thing about Colbert. Hate him for his politics, fine, but he really can be hilariously funny. One of my favorite shows, then and now, was “Strangers With Candy” on Comedy Central circa 2000. He was a supporting player but stole every scene he was in. He turned political during the Bush era but succeeded wildly at it with lefties thanks to his bite, most famously at the 2006 White House Correspondents Dinner with Dubya sitting right there in front of him.

What the hell happened to that guy?

Lay the politics aside. What professional comedian would allow a joke this lame to go out under his banner?

That wouldn’t make the cut as a gag even coming from some random Trump-hating wiseguy on Twitter. They’d recognize it for what it is — a self-own, a goof so feeble that it embarrasses the source more than the target. It’s unimaginable that CBS’s highly paid late-night guy would greenlight it. And yet here we are.

Right, true, not every joke lands. Even the best swing and miss. But the above tweet isn’t an aberration. Look at the caliber of stuff going out on the official “Late Show” account lately:

What? Trump himself is more spontaneously funny than any of this. It’s not that the jokes aren’t laugh-out-loud good; they don’t need to be if they’re satirical and their points are trenchant. But at least draw blood. There’s not a drop evident anywhere here. It’s all variations of “TRUMP IS STOOPID.” How can that be? There’s a team of professional comics working on this stuff.

I’ll give you three theories, none of which is mutually exclusive. One: He’s lost his edge as he’s aged. He’s made all the Trump jokes he can think of and now he’s down to correcting presidential misspellings. Happens to everyone. See, e.g., Letterman 1982 versus Letterman 2014.

Two: He’s gone corporate. You work for a behemoth with a national reach like CBS and you’ll inevitably find yourself pitching to the lowest common denominator of America’s late-night audience. Can’t do a bunch of involved political jokes now that might have played with the news-savvy viewership of “The Colbert Report.” Too many CBS viewers won’t get them. Ergo, spelling jokes.

Three: He was seduced, and has now been ruined, by “clapter.” The entire story of “Daily Show”-era political humor is the drift from funny to funny and trenchant to funny and outraged to outraged without so much funny. Maybe Colbert’s arrived at the final stage, pure ridicule shorn of any attempt to be funny or insightful. He’s identified the villain for his audience. He’s duly mocked him, laughs be damned. Now’s the part where people clap. That’s how this transaction works, right? Colbert kept up his end of the ridicule bargain. What more is he supposed to do? Make you laugh?