MOORE AND HARPER ON THE SITCOMBACK TRAIL

A scene from the 1970 premiere of a famous sitcom. . . .

Mary Richards: You think I’m some kind of pushover, don’t you?

Rhoda Morgenstern: Right.

Mary (halfheartedly gathering courage): Well, if you push, I might just have to push back--hard.

Rhoda: Come on--you can’t carry that off.

Mary (sheepishly): I know.

There’ll never be another sitcom like “The Mary Tyler Moore Show.” Life goes on, though, and so do Mary Tyler Moore and Valerie Harper, whose roles as an All-American prom queen and an All-American schlepper, respectively, brightened TV and helped make “The Mary Tyler Moore” one of the funniest sitcoms ever.

After “The Mary Tyler Moore Show,” Moore overcame some TV and stage failures to finally strike it bigger in theatrical and TV movies, while Harper parlayed a four-season “Rhoda” spinoff into relatively low TV profile.

How ironic that these former TV chums are now attempting sitcombacks in the same season--Moore in her ho-hum “Mary” series on CBS and Harper as a comedic mom and homemaker in “Valerie,” premiering at 9:30 p.m. Saturday on NBC (Channels 4, 36 and 39), thereafter to air Mondays at 8:30 p.m.

“Valerie” is nothing to build your evening around, but it at least allows Harper to change beats and discard Rhoda more successfully than Moore has shed the old Mary.

“Mary,” which CBS had envisioned as its Wednesday night mid-season savior, began modestly and went down from there, drifting into the bottom half of the Nielsens. On March 25, it will be shifted to a new, later time period on Tuesday nights opposite--tough luck--ABC’s terrific “Moonlighting.”

One of the problems is that the new Mary--a refined single woman with a media career punctuated by unrefined, off-the-wall characters--is still the old Mary, only less funny. So comparisons with “The Mary Tyler Moore Show” are inevitable, and--desite Moore’s sitcom gifts--inevitably unfavorable.

At least Harper may avoid the Moore-is-less comparison. There is barely a hint of the New York-edged Rhoda in “Valerie,” where Harper is the conventional harangued mother of three sons--a 16-year-old and 13-year-old twins--and wife of a seldom-seen international airline pilot.

Valerie even has a goofy next-door neighbor (Christine Ebersole), who shows up on the second show, supplanting the goofy sister-in-law who appears on the premiere, a pilot that was taped months earlier.

The new Valerie is one of sitcomdom’s bold new women. First came the shirtwaisted homemakers who got their kicks vacuuming and breading cutlets. Then came the attache-bearing, microwaving career mothers and wives. Now, “Valerie” seems to signify it’s again safe for sitcom women to be non-careerist stay-at-homes, as long as they have minds of their own and dress better than Jane Wyatt did in “Father Knows Best.”

Although she’ll later get a part-time job, Valerie spends the first two episodes being a mom trying to cope with her kids (“Do you have to do your homework while you’re eating?”), particularly 16-year-old David, played by Jason Bateman, who was the awful teen in NBC’s awful “It’s Your Move.”

In the slow-starting premiere, Valerie frets when David falls for a not-too-bright 24-year-old woman, whom he brings home to meet his mother. That produces a howl of a scene that should remind everyone just how wonderfully funny Harper can be.

David is also Valerie’s worry in the faintly amusing second episode, when he wants to snub a terrific girl who he thinks is not good-looking enough to take out in public. (“Hilary is a five, maybe a six, and on my worst day, I’m an eight.”)

In both stories, Valerie sets her son straight. After weak protests, he dutifully follows her advice, which is every parent’s fantasy, of course, but practically no parent’s reality. That illustrates a basic difference between “Valerie” and the funnier and truer-to-life family on “The Cosby Show,” for example, where the kids are real and often reject the wisdom of their parents.

Harper has the skills to bring out the terrific even in the terrible. Still, you have to wonder about “Valerie,” based on these so-so first two shows, which the producers seem to feel are their best feet forward.

Bateman does a nice job as David, who becomes the first sitcom kid to utter a “damn.” And Danny Ponce and Jeremy Licht are all right as the twins. In the main, though, it’s all pretty routine stuff.

Rhoda Morgenstern would scoff.