I think Garry Trudeau should retire and ride off into the sunset, because there’s nothing for him to make fun of anymore. The self-involved prep school Baby Boomers who compose his cultural milieu are past the point of ridicule now. Sure, they were funny during the Clinton ’90s, when they were in their forties and unbuttoning their shirts a button too low. But now they’re just old and sad, drifting off into a suburbia still protected by their “right way of thinking,” and increasingly irrelevant.

Jonathan Alter was Andover class of ’75, and these days his Bloomberg View column is demonstrating what exactly that means in 2011. It features all the Boomer hallmarks — the blind faith in higher education, the perpetual student-ism, the nodding support of those from alternative backgrounds — but with a new kind of lazy contentment. Alter’s Sep. 22 column “Worried About America?: Visit a Boys & Girls Club” didn’t even have a joke title. He was sincerely telling us to go visit a boys and girls club. Because he recently did. And he found some very special things inside:

This week, I served as one of five judges in the Boys & Girls Clubs of America National Youth of the Year competition. This is like the Miss America pageant, except that instead of judging contestants by how they look in a ball gown, we were assessing things like “Moral Character,” “Public Speaking” and “Obstacles Overcome.”

Talk about a man-bites-dog story: The adults in the room — from a senior White House official to an executive with Major League Baseball — stood in awe of 17- and 18-year-olds.

Hey that’s great, Dad. So the Jetta is in the driveway?

Jonathan Alter is proud of all the good work he’s done. Like launching his hagiographic Obama book The Promise in time for the 2010 midterms. And anointing buddy Rahm Emanuel Newsweek‘s “King of Chicago” (Gery Chico who?) during his mayoral campaign. And, as recently as  August 26, declaring “You Think Obama’s Been A Bad President?: Prove It.” See, the burden of proof is on us. Once a feisty MTV political consultant getting out the Clinton youth vote in ’92, Alter is now filled with empty-nester self-satisfaction.

Is that why Tina Brown put him out to pasture? In April, Alter became the last of the much-whispered about “Newsweek Six” to get his Christmas bonus early — following Howard Fineman, Michael Isikoff, Fareed Zakaria, Jon Meacham, and Evan Thomas. Line them all up, and it’d look less like The Usual Suspects and more like The Big Chill. Fineman quickly became senior politics editor at the Huffington Post. Isikoff (who, during Monica, famously couldn’t get off a shot while Drudge hit the game-winning three) went to NBC News. Zakaria went to Time, Meacham to Random House publishing and Thomas to the journalism department at Princeton.

Noting “changes afoot,” and slyly referring to his “defunct” Newsweek email addresses, Alter left the Newsweek building after filing his final bit of optimism, “Arne Duncan’s mission to fix America’s schools has a shot at success,” on April 3. Out went the Walden College grads and in came flamboyant post-Boomer Andrew Sullivan and “crazy-eyed” newsstand gimmicks.

For a while, it was fun to watch Alter grovel, as he did in his early days as Friday columnist at Michael Bloomberg’s new opinion publication. All of a sudden the true-blue liberal found himself condemning Mayor Bloomberg opponent Diane Ravitch as being some kind of teachers’ union stooge (Salon accused him of “directly attacking prominent critics of the boss”). For one shining moment, it seemed like American journalism was changing, and aging access reporters like Alter — pushed out by ambitious Washington and New York-melding media liberals like Jonathan Chait — would now have to become center-right hitmen in order to survive.

Not to be. Instead, Alter at Bloomberg has fashioned himself one of the most consistently tame liberal soapboxes in the business. Since Bloomberg View is less than a year old and statedly “ideology free” (at least in unifying theme), it allows its big names to set their own tone. For Alter, it represents his membership to a self-satisfied new club. He joins Dan Rather (HDNet) and Keith Olbermann (Current TV), as well as Keith’s nutty professor boss Al Gore (he of the 24-hour telethons) in the world of the left-wing New Media: where the sugar daddies are big-time, so feel free to drone on, and on, and on.

Alter each week dwells in a ’60s-kid playpen, advising Obama to “channel LBJ” in passing the Jobs Act, needlessly rehashing the Clinton-Gingrich fights to score petty little points for Bill, and ascribing to the Bush years the title “America’s Lost Decade.” At this point, no cartoonist could even do justice to Jonathan Alter.

For all of Tina Brown’s liberal hysterics, at least one thing can be said for her Newsweek takeover: when she came in, one member of the campus protester generation marched on out. Whether Tina Brown actually facilitated that shift, we can only speculate. But I can’t imagine she misses Alter too much. The quality of his recent work more than confirms that.

But who knows, maybe he still has a few decent starry-eyed puff pieces left in him. Or maybe he’ll write a John Irving-style novel?