Johnny Carson kept his personal politics close to the vest. For the most part, so did Jay Leno and David Letterman.That’s not the case with the current roster of late-night comics.During Election Week, they might as well have slapped “Vote for Biden” stickers on their foreheads. Their behavior may have helped liberal viewers get a sounder sleep, but it didn’t result in a lot of laughs.“Looks like we’re finally sending the monster back to Mar-a-Lago,” ABC’s Jimmy Kimmel said Wednesday, before scolding those who voted for Donald Trump. Sidekick Guillermo Rodriguez led an intoxicated cheer for Jo…