At the time, “SNL” creator and executive producer Lorne Michaels pronounced them “the wave of the future” and Fey likened herself to a senior seeing “exciting freshmen” arrive. But as this latest season of the sketch institution comes to a close this Saturday night (with host Mick Jagger, and musical guests Arcade Fire and the Foo Fighters), there’s a growing sense that another “SNL” class is nearing graduation.

Wiig, Samberg and Sudeikis have been reported to be leaving, though Michaels has said any decision will wait until the summer. With a presidential election looming, an immediate exodus of all three is unlikely. Sudeikis plays both Republican candidate Mitt Romney and Vice President Joe Biden, and “SNL” has previously taken an all-hands-on-deck approach to election season shows.

Of course, the 2008 election season was a historic one for “SNL,” one that saw record ratings for the show as Fey returned — to much fanfare — to play Sarah Palin. This time around, no one is expecting Romney to choose a running mate that looks exactly like Andy Samberg.

A transition period, whether sooner or later, seems on the horizon. Perhaps more than any previous cast, this one has already expanded considerably from the show.

Wiig, of course, starred in and co-wrote the hit “Bridesmaids,” but even before that had notable roles in “Friends With Kids,” ”Paul,” ”Adventureland” and “Knocked Up,” among others. She has six films in some form of development, along with plenty of interest in a “Bridesmaids” sequel from her and her writing partner, Annie Mumolo.

Hader, who played Wiig’s husband in “Adventureland,” co-starred in “Superbad” and has numerous projects lined up, including a bit as Andy Warhol in the upcoming “Men in Black III.” Samberg, who made the film “Hot Rod” with his Lonely Island cohorts, Jorma Taccone and Akiva Shaffer, costars with Adam Sandler in the soon to be released “That’s My Boy.” Sudeikis’ films have included “Horrible Bosses,” ”A Good Old Fashioned Orgy,” ”Going The Distance” and “Hall Pass.” He’ll also be in Jay Roach’s comedy “The Campaign.”

The typical path used to be to exit “SNL” with a film based on a popular character — as Will Forte did recently with the box-office disappointment “MacGruber.” But this cast has been as visible outside of “SNL” as it’s been on it. Armisen even managed to launch another sketch show at the same time: IFC’s “Portlandia.”

With a cast of half-a-dozen stars, there hasn’t always been a lot of airtime for younger cast members. Most avid viewers would like to see more of featured player Jay Pharoah, whose knack for impressions of Denzel Washington and Will Smith is so good that he deserves a chance to show more range. The same goes for the more consistently used Bobby Moynihan (who’s made his strongest impact on “Weekend Update” appearances, including as “Drunk Uncle” and as “Jersey Shore’s” Snooki) and Nasim Pedrad, most famous for her sharp Kim Kardashian impression.

But this season has made clear that if anyone is being groomed for a larger role, it’s Taran Killam. As a featured player, he’s become a regularly highlighted performer, including impressions of Brad Pitt, Michael Cera and Bravo’s Andy Cohen. More than the other of the younger cast members, he’s frequently gotten sketches into the show, like the Parisian parody “Les Jeunes de Paris” and “J-Pop America Fun Time,” a similar, Japanese spoof of American perspectives on foreigners.

Still, it’s been an uneven season for such a strong cast. The show has sometimes been overly reliant on predictable cable news frames for political sketches and leaned too heavily on recurring character sketches with so little variety as to seem like reruns.

But when “SNL” is firing on all cylinders, it can be as good as it’s ever been. This year, those moments have typically come when an alum has hosted: Maya Rudolph in February and Jimmy Fallon for the Christmas show.

Such occasions usually bring back other former cast members, as well. If anything, the “SNL” universe has grown larger, spread out across TV shows and myriad movies — making a kind of constant revolving door for “SNL” cast members, past and present.

In that way, “Saturday Night Live” has more in common with the mafia than any other TV show: No one ever really leaves.

As the horror unfolded in real time, the Twitterverse gaped in astonishment. Juliette Lewis dryly noted, “Wow watching this ‘singer’ on SNL is like watching a 12 yearold [sic] in their bedroom when theyre pretending to sing and perform #signofourtimes.” And though Lewis graciously later deleted the tweet, praising her “great haunting melodies!” others were not as generous. As Eliza Dushku asked, “Who…..is…..this wack-a-doodle chick performing on #SNL..? Whaaaa?”

In the aftermath, the horror did not subside; it seemed to take on a morning-after life of its own. Mediaite opined that “The level of excruciating badness was so palpable, it felt like a wake” and none other than slow-jam master Brian Williams sent a note to Gawker about “one of the worst outings in SNL history… booked on the strength of her TWO SONG web EP, the least-experienced musical guest in the show’s history,” in the hope of receiving a trademark Gawker “withering, detailed critique.”

How did no one see this coming? Del Rey told MTV last week that she was “a little nervous” about the gig. “You just hope it goes well and you don’t f*** it up,” she said, but promising  “I’m sure it will be good.” And when she did a similarly catatonic performance on Jools Holland’s show in the U.K. last fall, the performance passed without notice. Anyway, with her distinctively David Lynch movie sound and the kind of looks that have landed her a modeling contract, you’d think she’d be money in the bank.

But putting a virtually untried performer on such an iconic platform was a move fraught with potential pitfalls. And for all her moody, Guess? jeans posturing, there seems an air about Del Rey of a woman who has not yet found her true voice. She is, after all, a self-proclaimed “gangsta Nancy Sinatra” — which is perhaps her way of warning us that she’s intentionally going for that naughty blond deer in the headlights effect. And just like Nancy — and Rebecca Black, for that matter — she owes a big career debt to her bigshot dad. Del Rey’s father, millionaire investor Rob Grant, helped with the marketing of her first album two years ago. Back then, she was still Lizzy Grant, the rich kid who grew up in upstate New York and went to boarding school in Connecticut. Months later, she had morphed into Lana, a mystery lady who “at one time lived in a New Jersey trailer park” and whose name sounds like a Mexican brand of cigarettes. The image, she explained, “came from a series of managers and lawyers over the last five years who wanted a name that they thought better fit the sound of the music.”

The former Elizabeth Grant will likely solider on. Both Ashlee Simpson and Ke$ha managed to bounce back from their disastrous “SNL” performances and, God help all our ears, live to sing another day. Del Rey has just been booked for a coveted spot at the South by Southwest festival, and “Video Games” is a respectable No. 44 on the iTunes singles chart. It’s far from the kind of post-national television debut bounce any artist would hope for, but it’s a better deal than most working singer-songwriters ever get. And if you saw the rest of the “SNL” episode, you know that Del Rey was far from the only cringe-worthy element of the show.

The week’s host, the ever-gracious Daniel Radcliffe, said this week that “It was unfortunate that people seemed to turn on her so quickly. I also think people are making it about things other than the performance.” But really it’s just the opposite. In an elegantly orchestral music video or on a well-produced track, Del Rey is all smolder and pouts. She can sing of being a “bad girl” and sell it. On live national television, she’s a still inexperienced girl, awkward and stiff and, frankly, boring. Her album will be released Jan. 30. Only then will we learn whether anybody’s really buying the woman who seemed to be the next big thing.

But even that was funnier than the cold open the week before, following Rick Santorum’s near-victory in the Iowa caucus. Santorum lost to the monotoned Mormon by just eight votes, and his statements on the trail since his rise in the polls must have seemed like belated Christmas presents to comedy writers. Surely Andy Samberg, the goofiest cast member, would let his freak flag fly, right? Instead, Samberg spent five minutes setting up a joke about Santorum’s 100-day, 99-county Iowa campaign, pledging to visit every county in America to beg for votes, even braving the “heavily armed population” of Monroe County, Tenn., that inspired “Deliverance” and the “thousands of angry pillow biters and doughnut bumpers” of San Francisco county. Why? Get ready for the punch line: “This is about the country that has given so much to me and to which I want to give something in return,” says Samberg-Santorum, “so that maybe one day, long after I’m gone, my grandchildren can look me up on Google and find something, you know, different from what’s there now.”

Samberg’s Santorum would’ve gotten more meaningful laughs if he’d just turned up wearing a foamy mocha-latte mustache, promoting the chocolate-frothy caffeinator as his official campaign beverage. Even Jay Leno had sharper barbs (“He lost by only eight votes … You know what’s ironic? He could have won if he’d just gotten the gay vote”).

It’s been that kind of year on “Saturday Night Live.” The Republican presidential field is an embarrassment of crazy-train riches. But the writers have been lazily broad-stroking caricatures of the candidates, and the result has been surprisingly edgeless and increasingly lame sketches. There’s no bite to Sudeikis’ Romney, played as a mere socially inept square. Kenan Thompson’s Herman Cain was a clueless, oversexed black man with dumb luck and box loads of pizza metaphors. “Fences. Jesus. Papilloma. Eyeballs,” is the essence to Kristin Wiig’s Michele Bachmann — exact words borrowed from Wiig-Bachmann’s actual post-Iowa closing statement on the Jan. 7 “Weekend Update” (even the pith of “Weekend Update” anchor and “SNL” head writer Seth Meyers has dulled this year).

The “SNL” writers wrote off Newt and Ron Paul as viable candidates early in the game — surge be damned — so Bobby Moynihan has been left to grin idly in his Phil Donahue wig, when he could have, at the very least, seized an opportunity to spoof Gingrich’s amazing concession speech in Iowa, a study in aggressive passive-aggression, directed at Romney. Why wasn’t more made of Romney’s relationship to Jon Huntsman, a distant relative from a rival Mormon clan — where’s the “Big Love” sketch? At the very least, a “Romeo and Juliet” number with one of Huntsman’s daughters and one of the Romney boys. I’d even take a “Brady Bunch” skit. With each GOP contender flitting away — after Huntsman’s exit on Monday, we might never see two Republican Mormons running for president — so too goes another missed opportunity, the unrealized jokes piling up like stacks of yesterday’s newspapers.

Though “SNL” is not strictly a political-satire show like “The Daily Show” or “The Colbert Report” — two shows that have had no problem doing both smart and funny work in recent months — it does have a reputation for edgy political commentary, for shaping the national conversation. And while the “SNL” cast and creators often dismiss criticism of the show by suggesting that everyone believes the show’s heyday is when they were in high school, you don’t have to go back far to find a golden age of political comedy. During the 2008 election, the sketch-comedy show was even lauded for being a game-changer: Tina Fey’s entitled, ignorant Sarah Palin (“I can see Russia from my house”) was spot-on, and Amy Poehler perfectly evoked the rage and righteous indignation of her Hillary Clinton, and made viewers appreciate her plight for the White House, her resentment of Obama, her outright hatred for Palin. Neither required too much embellishment — that was the beauty of the sketches, and the performances — and as a result, our hunches about the various candidates were confirmed, through these laugh-out-loud depictions, during an election when so many Americans were sitting on the fence. And so these enter the pantheon of iconic “SNL” political impressions: Chevy Chase’s buffoonish and clumsy Gerald Ford, Dana Carvey’s catchphrase-obsessed George H.W. Bush, Phil Hartman’s white-trashy fast-food-bingeing womanizer Bill Clinton (and later, Darrell Hammond as a cool-headed smooth-talker through Whitewater and Monica), and Will Ferrell’s willfully ignorant playboy Dubya.

“SNL” has had an undeniable impact on the culture, on the way candidates are perceived, and as recently as the last election, it has proven how persuasive it can be — or, at least how it can nudge us in a direction we were considering. And edgy is best left to the professionals, the Stewarts and Colberts. To be fair, that’s not “SNL’s” aspiration or mandate. They just need to make viewers laugh. Because if viewers are laughing, it means they’re listening.

And this is where “SNL” is failing viewers right now, by resting on those laurels of 2008. They’re writing as if, in the words of Vanessa Bayer’s moderator in “Yet Another GOP Debate” sketch from October, “No one is watching, so the stakes are low.” As the race whittles down, and Republicans seem more and more likely to settle for Romney, pens need to sharpen — right now, it is too easy to watch “SNL” on DVR, with a finger on the fast-forward button, searching for a chuckle. Sudeikis is leaving at the end of the season: It’s an opportunity to have more fun with Romney (please let it be Taran Killam). And must we really endure another year of Fred Armisen’s Obama, as a too-calm, emasculated, disempowered world leader? It’s a dreadfully boring narrative thread.

But if these writers had a hard time making the present cast of GOP characters interesting, it’s hard to imagine that they’ll be inspired by the next 10 months of Romney and Obama. We expect Romney and Obama to be cautious candidates — but that’s hardly an excuse for such timid and uninspired satire.

Unfortunately, not even Lady Gaga’s presence could save the underwhelming reunion of J.T. and A.S. in “3-Way,” a song that wasn’t only musically boring (if Justin Timberlake and Gaga can’t get some interesting harmonies going in your song, there’s a problem), but about as tepid as a number about having sex with Lady Gaga  could be. 

Reprising their “Night at the Roxbury 2.0″ characters from previous songs, the manscaped Timberlake and Samberg give a halfhearted performance that only shines in a beginning sequence with Patricia Clarkson and Susan Sarandon (leftovers from “Motherlover”). The rest of the number they phone in, letting the costumes they stole from the set of “In Living Color” do most of the work. Gaga gets a couple of good cat howls in the background to make up for the lack of musical gusto, but even the song’s theme (a magic rule stating that it’s “not gay” to be freaking with another guy if there’s a chick in the middle) could have been stretched farther and funnier to make it a true Lonely Island digital short.

Ah well, I guess they can’t all be “On a Boat.”