The Watergate tapes were America's obsession during the brilliant run of "The Mary Tyler Moore Show."

The Alec Baldwin tape obsessed America last week, amid the brilliant run of NBC's freshman sitcom "30 Rock."

Baldwin's voice-mail tirade at his daughter (he called her a "rude little pig" and seemed confused about whether she was 11 or 12) was leaked to the celebrity Web site www.TMZ.com, presumably as a vindictive strike in the actor's divorce from Kim Basinger.

On it, Baldwin unleashed a Nixonian rant at his daughter, who had failed to pick up his telephone call at their agreed-upon hour.

Baldwin lost me, finally, at "rude little pig"; before then I was rooting for him as if he were fictional — a man by the name of Jack Donaghy, fierce, strange and even cuddly, a whiz at the microwave oven business, for which he'd been handed the entertainment reins at GE-owned NBC.

That's who Baldwin is on TV, on "30 Rock."

Low-rated in its first season, which concludes tonight, "30 Rock" has more legs than "The Office" because it's grounded in a relationship that has all the stirrings of Mary Richards and Lou Grant in "The Mary Tyler Moore Show."

As Liz Lemon, plucky executive producer of a variety show in the way that Mary Richards produced the local news in Minneapolis, Tina Fey is slouching toward sitcom iconography — independent single woman holding her own among boy-men in a city in which she is positively alone.

Fey (more of a writer chick at heart, really), though in her 30s, comes to the game less polished than Moore, who had already starred in "The Dick Van Dyke Show." But Fey has relaxed into the role now, playing her ambivalence for well-earned laughs.

"There is an 80 percent chance in the next election that I will tell all my friends that I am voting for Barack Obama, but I will secretly vote for John McCain," she told a love interest recently.

Baldwin, who plays the mercurial, tone-deaf network head Donaghy, is an ex-movie star gone half-to-seed, bloated and slouched. Together, the reluctant entertainer (Fey) and the outsized one (Baldwin) make great music; right now, it's hard to imagine having seen enough of them in scenes together.

You can trace their chemistry back to weekly scenes in which Mary would step into Grant's office for a chat, the boss-employee relationship doing a slow build into something else — from pseudo boss to pseudo father — as when Liz tried to quit her job last week and move to Cleveland with her boyfriend after spending a magical weekend there.

"For God's sakes, Lemon, we'd all like to flee to the Cleve," Jack told her, " ... but we fight those urges, because we have responsibilities."

It's difficult to capture in words the joy of hearing Baldwin intone "flee to the Cleve" in that low, rich grumble he's employing (I kept waiting for it on his voice mail, but alas, it never arrived amid the fit of pique).

In tone, "30 Rock" is closer to "The Simpsons" than "Mary Tyler Moore" (Cleveland as paradise is a writers' room joke, as was the hilarious scene a few weeks ago in which Baldwin, in a dream sequence, appeared as Thomas Jefferson and was booed at a taping of "Maury").

But the show, which has been renewed, is our next great workplace comedy. You couldn't set "Mary Tyler Moore" at a news station today without somehow acknowledging that local news doesn't really exist anymore. And a scandal like Baldwin's voice-mail tantrum at his daughter breaks into the news like it is news, practically presidential, but with no subpoenas required.

Somehow, you feel Liz Lemon would know what to do.