Sometimes the best way to think about Congress is by going to the movies. That happens to be the case when it comes to this week’s legislative fight over the estate tax. Many Republicans want to repeal the tax, or reduce it. Many Democrats and some Republicans insist on keeping the old levy.

The showdown will come tomorrow, when Republicans will figure out whether they have enough votes to overcome a likely Democratic filibuster.

Lawmakers who have already decided how they’ll vote might want to head down Connecticut Avenue to take in “Keeping Up With the Steins.” The movie features two Los Angeles families competing to host the splashier bar mitzvah.

Literally splashier – the first bar mitzvah party takes place on an ocean liner. A trained orca dons a yarmulke and leaps through a giant Star of David. The second family wants to top that by renting Dodger Stadium. Neither parental pair seems especially concerned about the effect on their 13-year-olds.

All this has a bearing on the estate-tax issues preoccupying Congress, the first being fairness. Democrats and their allies on the estate tax say that repeal will somehow hurt the rest of society. Their argument starts out as a fiscal one – Republican John McCain of Arizona, for example, has waffled on repeal because of concern about the federal deficit.

The underlying premise is that the U.S. economy, in its way the greatest bar mitzvah competition of all, is a zero-sum game. If lawmakers abolish the estate tax then the deficit will widen, they argue.

There is also a more general faith in Congress that flamboyant wealth in one sector of society actually hurts another. People such as Bill Gates Sr., have been suggesting this for years. The father of Microsoft Corp.’s founder and the world’s richest man once told the Minneapolis Star Tribune that “the estate tax has made a contribution toward curbing the accumulation of enormous wealth in certain families, which really endangers people’s sense of starting equally in the same race.”

Envy is driving lawmakers as well – their constituents’ envy, and, perhaps their own. Lawmakers say they are standing up for lower earners when they are cutting off the dependents of the wealthy. In this sense the estate tax game isn’t “Keeping up with the Steins”; it is “Making Sure All the Other Steins are Also Kept Back.”

The ultimate issue the culture is grappling with here – whether on the screen or on the Hill – is what happens to the children who get all the goodies. Not what happens to their pocketbooks, but what happens to their souls. You don’t have to see “Keeping up with the Steins,” to know what I’m talking about. Stop by any weekday at 3:30 p.m. at a private or suburban junior high school. No matter their ethnicity, the children waiting for their rides gaze out from behind a thick glaze of entitlement.

Wealthy people who back the estate tax are like the fathers of bar mitzvah boys. They write the checks for the weddings at the St. Regis, the paintballs parties for 200, the multiple business-class tickets to Australian resorts.

But they know they’re wrong to indulge. They sit in their cars alone at night and anguish over their fatuous offspring. But they can’t stop themselves. So they tend to support the estate tax, to prevent or limit intergenerational spoiling in the future. Theirs is the desperate plea of the serial spoiler: “stop me before I spoil more.”

None of these arguments stands up. The budget one is flimsy. If you are really concerned about the federal budget, attack programs that cost trillions. President Bush’s new Medicare drug commitments are a good target, for example. As for the cost of the giving up the estate tax, estate-tax fans exaggerate here. Wealthy families who keep the money will spend it on some other activity, which will also be taxed – and create jobs as well.

In its silly way, the bar mitzvah market itself demonstrates this. Two generations ago, a bar mitzvah was a simple affair involving cupcakes. Weddings too were often modest. Now everyone and his brother rents a hall and hires a rap DJ. Yet ask a caterer: other people’s parties haven’t made the country poorer.

Even weaker is the argument behind the argument: that parents need the Internal Revenue Service as nanny to help them produce upstanding children. Inheritances do need to be curtailed. But it is the parents who need to summon the strength to do that curtailing.

“Steins” in its own way comes to the same conclusion: A long-absent grandfather materializes to act where parents fail to do so. One boy comes to realize that hiring an orca is too much. He insists on a smaller event in his backyard.

In short, it might be good to pause before assuming that a desire to cut back your own child’s cash translates into a right to control other families’ budgets. Bar mitzvahs, weddings – a child is easy to ruin. But every family deserves the chance to ruin its own.

Miss Shlaes is a columnist for Bloomberg News.