When Stewart leaves later this year, he will walk away from an audience that will no longer take the theater of media-driven politics seriously. And as a promoter of serious books, he leaves his fans better informed. He’s been a public service — Consumer Reports, by way of the long-dead National Lampoon. And for many in the press, he says what they’ve always wanted to say, using an unprintable word as noun, verb and adjective.

After his takedown of Glenn Beck, writing crazy talk on a chalkboard between bursts of discordant tears, nobody except those with a radio embedded in their molars could listen to Beck.

Can anyone act on a stock-buying tip from Jim Cramer, the CNBC host, after Stewart showed him promoting garbage before the financial collapse on a show that tries to make funny with your money, barking “buy, buy, buy!” while banging a gong?

And “Crossfire,” the original shout-fest on CNN that tried to prove there are no 50 shades of gray in cable’s view of politics, only one dimension of wrong, was left exposed and shamefaced for what it is after Stewart told the hosts to “stop hurting America.”

Stewart didn’t degrade politics and the press. He walked through a degraded landscape, the tour guide who’s also a smartass. In the cheerleading phase of the Iraq war, when dissident voices were labeled traitors, Stewart called out the lies on which the invasion was built, long before most Democrats, and most reporters, ever did. It shouldn’t take a comedian, obviously, to do that.

“Where will I get my news every night?” asked Bill Clinton, in a tweet following Stewart’s announcement.

He could start with the existing newscasts, mostly operating as platforms for new pharmaceuticals. He could consider holding anchors riding through the streets of Manhattan in “blizzard-mobiles” to higher standards. Or force them to ask, “What’s the matter with Kansas?” That’s what Stewart did Wednesday night, in a bit on an executive order from Gov. Sam Brownback that now allows people to legally discriminate against gay and lesbian state workers.