"Stepmom" is going to make you cry if director Chris Columbus has to poke you in the eye with a sharp stick to do it.

An insultingly manipulative weepy about a dying divorcee (Susan Sarandon) who finds her venom for the Other Woman (Julia Roberts) dwindling as she realizes her kids will have to rely on this woman as a mother figure, this picture is so obvious in its emotional machination that Sarandon's last Christmas morning is spent not with her family as a whole, but with each child in turn, just to drag out the tear-jerking.

Still, because of habitually potent performances by Sarandon and Ed Harris, as her ex-husband, and by Jena Malone (the young Jodie Foster in "Contact") as their bitter 12-year-old daughter, "Stepmom" was better than I had expected, even though it was also exactly what I had expected.

Sarandon and Roberts start out sharing a thick animosity, with Roberts playing an old-fashioned home wrecker who has been dealt a couple sympathy cards by way of Sarandon's reproachful malice. But in the course of the film every character gets handed a couple of bonding scenes, melting some of the glacial hostility being bandied about in the family.

Some of these moments are obliging (Roberts slyly aiding in her hateful step-daughter's teenage ripening) and others are just obnoxious (Columbus' ubiquitous "Big Chill"-style '60s sing-along), but most of them are manufactured and scheduled as if part of a do-it-yourself tearjerker kit, and it is up to the actors to rise above the material.

With Columbus behind the camera, there wasn't much chance the profuse pathos would have even a hint of subtlety (witness "Mrs. Doubtfire," "Nine Months") and the film is packed with elementary movie cliches (snow = magic), but in this outing the director's bad habit of yielding much control to his actors worked in the movie's favor. Sarandon and Harris play beautifully their former couple's ability to push each other's buttons. Those two and Malone embody absolutely the depth of their characters' feelings. (Yielding a bit too much, Columbus also allows Sarandon to a self-indulgent political statement about medicinal marijuana.)

However, Roberts and Liam Aiken, the kid who plays Malone's younger brother, leave a little to be desired.

Roberts has zero credibility in her character's fashion photographer career (she doesn't even know how to hold a camera), and she's been stuck in a generic role that could have been played by anyone from Winona Ryder to Cameron Diaz to Mira Sorvino to Sharon Stone with equal effect.

The boy is cute, of course -- Columbus must have a farm somewhere where he breeds these kids -- but he's relied on for comic relief far too often. I can only handle so many "aaawwww!" moments before I need an air sickness bag.

But for all its manipulation and neon sign authors' messages ("The truth is, the kids can have us both and be the better for it," Sarandon tells Roberts), I cannot dismiss "Stepmom" as I'd like to because it has such strong performances. The acting makes this movie.

If you go in for a good cry and you don't mind having your tears shamelessly manhandled, "Stepmom" will probably float your boat. Just don't bring along someone like me because the sound of my eyes rolling like a slot machine will be distracting.