"Then I had this crazy dream that my family were all just cartoon characters and that our success led to some crazy propaganda network called Fox News." –Bart Simpson   If Seinfeld had lasted as long as The Simpsons has, its finale would have featured a graying foursome closing in on 55 (60 for Kramer), far nearer, of course, to that much-derided condo in Miami Beach or to those discounted movie tickets than their selfish, or childish, or birdbrained shenanigans would have you believe. Eighteen seasons of The Sopranos–which ends in June after "only" eighty-six episodes–would make it statistically impossible for any of the original cast of wise guys not to be dead or incarcerated. And God only knows who would watch a Friends featuring a menopausal Monica and a Flomax-popping Chandler suffering from, as it’s wont to be called these days, BPH. No half-hour comedy has ever enjoyed as long of a run as The Simpsons, and, if Seinfeld (nine seasons), Friends (ten seasons), The Cosby Show (eight seasons, one of which matched Cliff and Claire directly against Homer and Marge on Thursday nights) and the other NBC Must See TV warriors are any indication, no half-hour comedy ever will.

Terribly animated (at least by Pixar or Dreamworks standards), unabashedly crude and, at times, prone to deus ex machina endings (including one featuring a robed, sandaled and bearded God who actually booms, "Deus ex machina!" as he sets things right), The Simpsons will present its 400th episode on Fox on May 20. It’s important to note the "on Fox" part, as there would be no Fox, let alone a Fox News, without The Simpsons. Indeed, the importance of The Simpsons to Fox was perhaps best illustrated in an episode of Family Guy, another Fox cartoon (and cheap Simpsons knock-off to some, delightful refurbishment of the genre to others), in which its protagonist rattles off some twenty-nine failed Fox programs that network execs had used to try and bolster the paltry Simpsons-Cops-America’s Most Wanted triad they were currently (and quite lopsidedly) using to entice primetime viewers.

Further proof of Homer’s influence on American culture was later made manifest when a Fox animator, Family Guy‘s Seth MacFarlane, crashed the gates of the Establishment and delivered the Class Day speech at Harvard’s 2006 commencement exercises. (Tim Russert did the honors in 2005; former President Clinton will take to the rostrum this year.) And though The Simpsons is typically associated with (and sometimes berated for) a leftist/liberal outlook, its pure literary, comedic and intellectual appeal is such that, during the run-up to the Iraq War, even National Review commentator Jonah Goldberg swiped "cheese-eating surrender monkeys," an epithet for the French coined by Groundskeeper Willy, for his own criticism of French refusal to join George W. Bush’s Coalition of the Willing.

Remarkably, after eighteen years, The Simpsons never strays far from a "smartest show on television" discussion. Actually, it never strays too far from much of anything it laid down in Episode 1, "Simpsons Roasting on an Open Fire," a Christmas special aired December 17, 1989, which featured the first mainstream animated characters who drank beer to excess, bet the family savings at the dog track and said "damn," "hell" and "ass" like the rest of us (and like their nonanimated TV cousins). The Daily Show, a current contender for that "smartest show" claim–and, like The Simpsons, often bandied about by the likes of Olbermann when they aspire to hipness–has juggled formats, correspondents and hosts (even if Craig Kilborn’s two-year tenure was long ago eclipsed, if not downright forgotten) during the show’s eleven-year stint on Comedy Central. The Simpsons, in contrast, has featured in three different decades the same characters, the same settings and the same scenarios. The Simpsons is the Gordie Howe of sitcoms. Creator Matt Groening has watched as knockoffs, heirs apparent both worthy and unworthy and even an entire network devoted to cartoons of the swearing, non-Saturday morning variety, come, struggle for a time and–more often than not–go.

Along with Bart’s hyper-aware gem printed above, "Yokel Chords," a recent episode first aired March 7, 2007, also featured what is perhaps to date the most succinct summation and critique of President George W. Bush’s foreign policy. "Brandine!" a startled Cletus–the show’s stereotypical hillbilly–exclaims upon stumbling across his fatigues-clad wife, "You’re supposed to be in Iraq, stoppin’ 9/11!" It’s a hilarious sentence, wrong in too many ways to count, and yet at the same time stunning, for–as we’ve seen for the past six years and change–this is actually how President Bush seems to think, speak and preside over history and his place in it.

Critics of The Simpsons often point to the lean years, the period roughly spanning the show’s ninth through fourteenth seasons that saw the introduction of a bevy of one-dimensional peripheral characters (the Afro’d, trapped-in-1976 Disco Stu and the overweight, misanthropic, and pony-tailed Comic Book Guy, to name two); and, by the producers’ own admission, an inundation of trite and contrived plots, such as a Martin Guerre-like scenario involving Principal Skinner, and a string of musical guest stars who always seemed to find backing band, stage, amps and time for an ill-fitting solo at some point during the show. And the family went to Japan, to Brazil, to England. Bart spent an episode stuck in Knoxville, Tennessee; Homer fled PBS fundraisers (actress Betty White among them) by absconding to a South Pacific atoll. Stephen Hawking even came to Moe’s Tavern (and landed a couple of punches with a mechanical fist attached to his wheelchair) a couple of times. A rumor even fluttered about in 1996 that Springfield would be abandoned for "Cypress Creek," a ridiculous planned community primed to spoof the likes of Disney’s Celebration, Florida. But in leaving their ranch home at 742 Evergreen Terrace in Springfield, and by letting flesh-and-blood guest stars fill in for the fictitious and familiar Springfieldianites (as Marge calls them), The Simpsons had also abandoned the skewering satire of middle American life that had engineered the show’s initial success.

Writing in Slate in 2003, Chris Suellentrop denounced Matt Groening’s "sitcom" for degenerating into a "cartoon." In short, longtime fans felt, the show had become a parody of itself; the characters were merely behaving as zanier versions of their earlier selves–drinking more beer, getting worse grades, belching more often–and it had become boring. Still, demonstrating the self-awareness that had always made The Simpsons unique among its primetime peers, it was during this creatively barren period that the show spawned Comic Book Guy’s catchphrase, "Worst. Episode. Ever," perhaps The Simpsons‘s most famous contribution to American slang since Homer’s ubiquitous "D’Oh!"–and a fairly accurate interpretation of diehard fans’ reactions suddenly emanating from their Internet soapboxes.

After a lackluster 300th episode (featuring skateboarding legend Tony Hawk and MTV-band-of-the-month Blink-182), though, The Simpsons struck back. Bush 43’s America, after all, had begun to resemble the Bush 41 America from which the show originally had spawned. Homer was sent to India after Mr. Burns outsourced every job at the nuclear plant, only to be sent home after conferring benefits, transferable sick days, vacation time and general laziness upon his South Asian employees–"the American sense of entitlement," according to Lisa–and Mr. Burns was financially forced to bring the plant back to Springfield. Another time, after suffering from amnesia caused by a head injury, Marge was prematurely released from the hospital because, according to her doctor, she’s "as well as her insurance will pay for." Life, perhaps, had become more ridiculous and, in turn, more susceptible to ridicule.

And after Number 400, while indomitable rumors about Tony Soprano’s impending doom will continue to swirl about, Matt Groening and Co. will prepare for The Simpsons Movie, set to open July 27. The film may soar; the film may bomb; but, come autumn, Season Nineteen will begin on Fox, and Bart will be 10, Lisa a second-grade know-it-all and Maggie an incommunicative infant. Scheduled to guest star is Stephen Colbert. Which network was he on in 1989?