Remember when late-night TV used to be entertaining — and actually funny?

You used to be able to turn off the tube and go to bed with a smile on your face.

Steve Allen, Johnny Carson, Merv Griffin, Joan Rivers, Jay Leno & early David Letterman, Arsenio … they were entertainers, first and foremost.

Their main shtick was topical jokes, quips and silly sketches. Their material was PG with an innocent hint or wink of R now and then.

In their monologues the founding fathers of late-night were gentle, equal-opportunity mockers. They knew how far to go when they made fun of their fellow Americans, movie stars or presidents.

You didn’t really know if they loved or hated Richard Nixon, my father or Bill Clinton, or whether they were conservatives or liberals or Republicans or Democrats.

It didn’t really matter what their politics were anyway. They weren’t hosting cable TV opinion shows, pushing their own opinions or trying to rile us up.

They and their writers and guests were trying their best to entertain and please us at the end of our day, not tick us off.

And now in 2017 we have the irrepressibly obnoxious Stephen Colbert.

Not only is Colbert not nearly as funny as he, his fans and the rest of the liberal media think he is.

But he’s also a proud, in-your-face liberal who’s decided it’s his partisan duty to pander to his political base every night by bashing President Trump in childish, vulgar and offensive ways.

Colbert’s crude homophobic joke about Mr. Trump’s relationship with Vladimir Putin on Monday didn’t get him fired from CBS the next morning.

It didn’t spark a national campaign calling for advertisers to abandon “Late Night With Stephen Colbert,” either, but it did start a twitter storm in the media.

Conservatives and gay groups called for CBS to do to Colbert what Fox News did to Bill O'Reilly — send him on a long vacation and never let him back in the building.

It’ll never happen. Colbert is a liberal. Liberals don’t get fired by TV networks or get hounded out of their jobs by their liberal lapdogs in the media.

Colbert has said he doesn’t intend to apologize for what he said. He doesn’t have to.

Since he’s a liberal, and liberals are hypocrites, anything Colbert says or does that is politically incorrect or insulting or slimy is quickly forgiven.

Plus, thanks largely to the victory of his nightly punching-bag-in-chief, President Trump,Colbert has vaulted to the top in the late-night ratings race.

Colbert is a big money-maker. CBS is never going to slaughter its prized cash cow, whose ratings are sure to spike for a while because of the flap over his tasteless comment.

He’ll have to be careful and censor himself from now on so he doesn’t offend his gay viewership.

Since few Republicans, Flyover People or Trump voters watched Colbert’s show anyway, his vulgarity won’t cost him many ratings points with those demographic groups.

From now on, he can continue beating up President Trump like he’s on MSNBC, not CBS. And he can continue delivering his learned spin on tax reform and climate change to his fans.

Colbert will have his fun for a while, anyway. But I can hear the greats of late night — Steve, Johnny and Merv — spinning in their graves. And they’re not laughing.

Copyright ©2017 Michael Reagan