She pulls a stool to the counter and bends low, hands on her knees. "Alice," she whispers. "Would you like to make a cake?" More than a year later, my daughter still recites the sweet particulars of this event: standing on that stool in her Nanny's kitchen, creaming the butter and scattering flour over the countertop, licking chocolate off the spoon.

At its best, a child's relationship with a grandparent is idyllic, a deep familial bond that is free of the sometimes wounding intensity that flashes between parents and children. It is this ideal, the seniors' lobby would have you believe, that quivers in the balance in the case of Troxel v. Granville, the so-called "grandparents' rights" case argued Wednesday before the Supreme Court. More than a dozen organizations have filed briefs on behalf of one side or the other, scattering much overwrought language about the future of the American family along the way. Those weighing in on the grandparents' side warn that the court could undermine statutes in all 50 states that permit grandparents to petition for visitation with their grandchildren.

But I can't respond as anything but a parent, and for a parent, what's at stake in the case is this:

Imagine that a judge, with no finding that you are neglectful or abusive, decides that once or twice a month you have to send your children away overnight. It might be to the home of someone with whom you have a bad history, or whom you suspect of being a little too old and frail to handle your rambunctious 6-year-old, or who actively dislikes you. You do not have a choice, even if your child's grandparent is Livia Soprano. And it makes no difference that your 4-year-old daughter is having night terrors, or is going through a phase where she needs her Barbie nightlight and her Squirtle sippy cup and the mangy doll she drew hair onto with her blue magic marker, and even then won't go to sleep unless you sing the dopey song you made up when she was 2, that time she had chicken pox and itched all night. Good luck communicating the warp and weft of that routine to a couple with whom you just spent a few years in family court hell.

Oh, and it cost you $30,000 in lawyers' fees to get here.

This is very close to what happened to Tommie Granville Wynn after the father of her two little girls killed himself, in 1993. The father's parents, Gary and Jennifer Troxel, sued for visitation of the girls, then 1 and 4, and won a court order--including one overnight visit a month and a week every summer. The mother objected, not to their having a relationship with the children but to the extent of the visitation, especially the overnights. (And perhaps, the subtext of the case suggests, to the intensity of feeling the bereaved grandparents brought to the cultivation of their granddaughters.)

Her appeal was upheld by the supreme court of Washington state, which overturned the entire statute in question, saying that parents have a constitutional right to decide with whom their children should associate, unless it is shown that they are doing the children some actual harm. The Troxels are asking the justices to revive the statute, saying it should be enough for grandparents to meet its vaguer standard of showing that their continued relationship with a grandchild is in the child's "best interest."

Judging by their questions at oral argument, the justices are unlikely to oblige. They seemed especially offended by the breadth of the statute, which said that "any person" could seek visitation with a child at any time. They may do little more than affirm the state court on this one aspect of its decision, writing a narrow ruling that would have scant impact on states with more tightly drafted visitation laws.

This would be a pity. In a perfect world, the justices would seize this chance to make clear that partisans are debating more than one issue here and exploiting the useful confusion that results. It is quite legitimate for a state to empower grandparents in cases of parental negligence or abuse or absence. Several states already recognize distinct rights, in both custody and visitation, for grandparents (and others) who have served as de facto parents.

But the subtler cases, in which good-enough parents fall out with grandparents, can find no help in the law. Something has gone seriously awry when a parent rejects the open-handed offering of a grandparent's love. How many people, after all, have the patience to help your 3-year-old bake a cake from scratch? But the state has no magic tweezers that can pry the appropriate parental caution apart from the jealous act of family spite. Love and loss and pettiness and narcissism are wounds for which there is no legal cure--or only cures that tamper with the essence of good parenthood, which is to feel an investment in a child's well-being that no one else on the planet can match.