Oh my! No one told us David Letterman was actually funny these days! Thanks for the giggle-inducing tip, Andrea Mitchell!

Earlier this year, the “Late Show” host called Rachel Maddow the smartest person in all of journalism. We’re still snickering over that one. And last night, he was at it again, proclaiming her “the smartest person on television.”

If that wasn’t a comedy bit, here’s one possible explanation:

After basking in the MSNBC host’s sheer brilliance, Letterman was overcome by the need to kick it up a notch. She isn’t merely the smartest person on TV — she’s the smartest person in the whole wide world! Paging Mensa …

Ha! That’s almost as funny as when Maddow suggested Nancy Pelosi should have a building named after her. Or the snort-worthy time she said the Citizens United decision “got rid of all the campaign finance laws in this country.” All of them.

Her genius is staggering. But hey, dishonest lefties have to stick together.

And clearly, one-man brain trust Dave Letterman knows smart.