Every actor who plays the president on “SNL”– Chevy Chase, Dan Aykroyd, Dana Carvey–gets a major publicity boost, but Ferrell, 33, may be the most unlikely Oval Office star yet. Though he’s been working on the show for six years, his signature characters–sternly lovable Janet Reno, Marty the unhip music teacher, Craig the overzealous cheerleader–are vastly more recognizable than their creator. “When I first started ‘Saturday Night Live,’ I remember thinking I’d better take the subways a lot, because once we do our first show, I’m going to be mobbed,” Ferrell says. “I’m still taking the subway.” He’d better enjoy the ride while he can. Ferrell’s squinty, verbally challenged Bush gets funnier by the minute–so much so that last week he was the centerpiece of an unprecedented double dose of live “SNL,” on Thursday and Saturday. Ferrell has movie deals–and not movies about “SNL” characters, either–all over town. Even “SNL” executive producer Lorne Michaels, who goes out of his way to not play favorites, admits that the show’s record-high ratings have come in large part because of Ferrell. “He’s the center pillar,” says Michaels. “He’s as good as anyone who’s ever done the show.”

So why isn’t Ferrell famous already? As the roaming interview indicates, he’s not very good at acting like a star. He’s still got the same 500-square-foot New York apartment he found when he debuted on “SNL.” He gave up driving his 1984 Toyota Camry only last year when the poor thing collapsed after 128,000 miles. Fact is, Ferrell never really wanted to be a performer. His dad, Lee, has toured for years as a musician with the Righteous Brothers. In a lesson that is sadly lost on the Charlie Sheens and Julian Lennons of the world, Ferrell was determined not to follow his old man into show business. “I saw the instability of it,” he says. “Even as a little kid, I said I was going to be a businessman.”

There was only one problem: Ferrell was talented. He started in comedy as a lark, taking classes with the Groundlings improv troupe after graduating from USC. Three years later he was on “SNL” (along with Groundlings Cheri Oteri and Chris Kattan). In a way, Ferrell isn’t your typical sketch-comedy star. He’s not a wickedly sharp impersonator, nor does he create wildly exaggerated characters that generate belly laughs. In conversation, he’s not the kind of guy who cracks a joke a minute–“Sometimes I feel like I’m continuously letting people down by being normal,” he says–and that realness carries over to his work. “Will’s like Chevy. He exudes a kind of goodness. There’s something sunny about what he does,” says Michaels. Which is a good thing, since he keeps bumping into the people he lampoons, as he did when Reno put on her trademark blue dress for a recent “SNL” episode. “I was a little nervous about meeting her, but she had a great attitude about it,” says Ferrell. “I told her that we’ve always portrayed her as a take-charge, almost superhero kind of character, and she kind of went, ‘Oh, be quiet!’ "

And now he’s joined the pantheon of players who have spun presidential parody into golden TV. Ironically, Ferrell never lobbied to play George W. He doesn’t “study” him, in the way Darrell Hammond stares at photos and videos of Al Gore to prepare for his performance. “It wasn’t this thing where I had a great Bush up my sleeve to unleash on America,” Ferrell says. “I just get a general sense of what I think he’s about, then I throw it away and let the performance come through.” Unlike his predecessors, Ferrell hasn’t been shy about criticizing his alter ego. In addition to telling the entire world that he voted for Gore, Ferrell twisted the knife by blasting the president with lines like “He’s probably drawing up plans to set up a mechanical bull in the Oval Office.” Any regrets about mouthing off? “I’ve learned it’s a double-edge sword,” says Ferrell, who ironically enough was raised in conservative Orange County, Calif. “As comedians we need to be a bit of a blank slate. Yet we’re in this era where heaven forbid you say anything slightly political. It’s a fine line.”

Now that Ferrell has arrived, the big question is: will he leave? Will he stick around and play W for a full term, or will he follow Eddie Murphy, Mike Myers, Chris Rock and the rest on the path from “SNL” to stardom? “I don’t want to stay past my welcome, like the guy two years out of high school still hanging out in the parking lot trying to pick up chicks,” he says. He just finished shooting “Zoolander,” a film with Ben Stiller and Owen Wilson, and is working on another movie, directed by Kevin Smith. He’s also one of the voices of “The Oblongs,” a twisted little animated series that debuts in April on the WB. Ferrell says he hasn’t made any decision about extending his contract, though he does have a new wife, Viveca, a fine-art auctioneer who lives in Los Angeles. He’s even bought a decent-size house there. Under the circumstances, a little encouragement from his bosses in New York would be nice. “I know they value me, but the phone hasn’t been ringing off the hook going, ‘We’ve got to sign him up right away’,” says Ferrell. “What’s the deal?” Listen up, “SNL.” If you want to keep Ferrell, you’d better stop beating around your Bush.