A 30-second spot on ABC's "Roseanne" will cost advertisers $375,000 next year. "Roseanne" is the No. 1 show of the past television season. It's a comedy about a woman struggling to balance the obligations of holding a job and raising a family in a world of sexism, oppressive bosses, dead-end jobs, pinched finances and other social forces generally unhelpful to people in her position. Whenever I watch, I can't help thinking: If this is the most popular television show in the country, why can't the Democratic Party win a national election? What has Hollywood figured out that the Democrats haven't?

I think something similar while watching "The Simpsons," the fantastic cartoon family show on the Fox network, which has become a national obsession since its debut last January. In a typical recent week, "Roseanne" and "The Simpsons" were ranked first and second among women ages 18 to 49. Among men in that demographically desirable group, "The Simpsons" was No. 1. ("Roseanne," feminist tilt and all, was in sixth place with the boys, just ahead of two NBA playoff games.)

Drug Czar William Bennett, looking for another publicity hit, recently took on Bart, the bratty 10-year-old Simpson son. Spying a Bart poster at a drug rehabilitation center, Bennett scolded, "You guys aren't watching 'The Simpsons,' are you? That's not going to help you." Apparently Bennett was taking his cue from a few humorless educators who have objected to a Bart Simpson T-shirt declaring, "Underachiever and proud of it." The czar beat a hasty retreat when the entire country responded as one with another Bartism: "Don't have a cow, man."

Bennett's dismay, whether feigned or sincere, was understandable. "The Simpsons" is no threat to drug rehabilitation. But, like "Roseanne," it is a direct challenge to Republican claims about middle-American values and concerns. The Simpson family seems a bit better off than the Conners of "Roseanne" -- the cartoon Marge Simpson doesn't work, an option not available to her all-too-fleshly sister, Roseanne Conner -- but the Simpsons, too, suffer from economic and spiritual alienation, not to mention an environment ravaged by nuclear and toxic wastes.

Advertisers aren't paying $375,000 for 30 seconds to finance the spread of left-wing agitprop. They're paying because people are watching. The producers and writers of "Roseanne" and "The Simpsons" -- though possibly Democrats and certainly not devoid of artistic ambition -- are creatures of commerce as well. If their shows have a liberal slant, it's a slant they correctly think will sell.

It's puzzling, therefore, that liberal politics can't sell. Even more puzzling: Hollywood's growing influence on the Democratic Party is widely believed to hurt the party in its efforts to reclaim the middle-American "silent majority." In their overt politics, Hollywood liberals are more interested in El Salvador and tropical rain forests than in the meat-and-potatoes concerns of traditional Democratic constituencies. Yet in its commercial life, Hollywood is brilliant at appealing to these very constituencies on liberalish themes.

"Roseanne" and "The Simpsons" both celebrate "family values," but with a left-wing twist: the family as a haven from the cruelties of the economic marketplace and as threatened by those same economic forces. Roseanne loses her job when she won't work overtime on the weekend. She is reduced to selling magazines by telephone. (To one prospect: "Well, I'm not interested either, but it's my job.") Up for a position as secretary to some deskbound bigshot, she's disqualified because she can't use a computer. Homer Simpson loses his job at the nuclear plant but despairs of qualifying for one at the toxic waste dump: "I'm not a supervising technician, I'm a technical supervisor!"

Roseanne and Homer are obviously heirs of Ralph Kramden and Archie Bunker. But the American Everyman has changed, and not just because one is a woman. For one thing, compared to their TV ancestors, the Simpsons and the Conners are well off. They live in nice houses, unlike the Kramdens' stark walk-up flat. Homer Simpson wears a tie to work. Dan Conner is an independent construction contractor.

In short, they are not your traditional "working class." They are the new middle class, making a good living during good times at post-industrial sorts of jobs, but obsessed with what the social critic Barbara Ehrenreich calls "fear of falling." It is this sense of the precariousness of middle class life -- fed by two decades of stagnant median family income -- that the Democratic Party has spectacularly failed to tap.

Then there's Bart. He's not a bad kid, merely an independent spirit. "How important is it to be popular?" he asks his father. "I'm glad you asked, son," says the hapless Homer. "Being popular is the most important thing in the world." Of course the episode really teaches the opposite lesson. And by pursuing his own independent course, Bart now is even more popular than Mr. Popularity-Above-All, George Bush. Which is a lot more than any flesh-and-blood Democrat can claim.