Do you remember the Fugitive Slave Act? It criminalized not only slaves who'd escaped to non-slave states, but also anyone who helped them flee. That law has troubling echoes in a new law, passed by the Republican Senate and House, that will make it illegal to transport a girl from a state requiring parental consent to get an abortion in another one.

The Fugitive Slave Act forced individuals who did not believe in slavery to collaborate in maintaining it. In states that had banned slavery, it compelled law enforcement officials to return escaped slaves to their masters, and coerced ordinary citizens into supporting this process. It isolated slaves from outside assistance, by threatening to imprison anyone who would help them escape.

Isolation is also the goal of the benignly named Child Custody Protection Act, which will become law if the House and Senate work out their differences. It targets girls who already feel they cannot talk to their parents without risking disaster. It leaves them on their own, because those who might have tried to help them will face jail if they do. Whether a sister, an aunt, a grandmother, counselor, or friend, anyone could be imprisoned for intervening to help. Meanwhile, the same Senators who backed it voted down an amendment that would have increased support for programs offering contraception and sex education--including abstinence education. Minors are also excluded from the FDA's recent ruling allowing non-prescription sales of the "Plan B" morning-after pill, so the goal seems to be less to prevent teen pregnancies than to punish them.

The House version goes further still, allowing parents to sue doctors who perform these out-of-state abortions. Both bills let the states with the harshest anti-abortion laws (and the least social support for women with children) control the actions of citizens in states with fewer restraints. They trample core federalist traditions, letting states with the most draconian laws impose their will on others. They even raise the prospect of similar federal or state laws prohibiting adult women from traveling to overcome state abortion bans-like a bill now pending in the Ohio House that bans abortion without exception, while making it illegal to transport or help women of any age to receive abortions in other states. This would seem to violate numerous judicial decisions affirming the right to travel and prohibiting one state from unilaterally extending its laws to another. But with Bush's recent court appointments, all sorts of longstanding precedents risk being subordinated to a hard-right ideology.

The proponents of parental notification have their reasons: Even minor medical procedures require parental notification; parents should be involved in the most consequential decisions of their children's lives; who wouldn't want to talk with their daughter about a choice this consequential? And people who see abortion as murder view the new prohibitions as a way to reduce the toll and protect young women from a morally destructive act. They see themselves as the new abolitionists.

But all of these arguments abstract the actual lives of the young girls who are pregnant. We're not talking about idealized families where trust and harmony prevails. We're talking about situations where trust has broken down to the point where a girl fears to tell her parents that she's pregnant. The reason could be incest, physical violence, or pervasive verbal abuse. It could be a tone of unremitting judgment that makes a girl fear condemnation no matter what choice she makes. It could simply be the certainty that her parents will force her to have a child while she is still unready.

Even where families are close, life can be complicated. I once met a woman who'd gotten pregnant and had an abortion at age 15. Like many teenagers who consider themselves invulnerable, she just hadn't thought it would happen. Her father had recently died and her mother was still distraught from the loss. Given her mother's situation, the girl felt she couldn't tell her about the choice she was making, and didn't until two years later when a condom failed and she had another abortion. The second time felt harder, but she told her mother this time, who supported her decision. She later felt ready to have her two daughters--"the girls God intended me to have."

Even though parents would often prefer that they wait, a majority of American teenagers will have had intercourse by their senior year of high school, and many when they're considerably younger. Because some will be clueless, others careless, and others just unlucky, more than a few will get pregnant, particularly where birth control and sex education are less accessible. Of the third of all U.S women who have abortions by age 45, 27 percent are Catholic (Catholics are 22 percent of the population) and 13 percent evangelical Protestants (who are 39 percent of the population). The communities most resistant to abortion are themselves not exempt from the choice. Although highly traditionalist parents often end up supporting their own daughters' abortions when no other good choices exist, young women from these communities aren't foolish to fear anger and ostracism.

The Fugitive Slave Act sought to isolate slaves through legal threats against their would-be emancipators, including those who'd help them once they'd reached so-called "free states." Escaped slaves were not even allowed to argue their story in court. The Child Custody Protection Act would erect similar walls around the lives of the young women it targets, silencing their voices and overriding their choices. In the name of honoring the primal community of the family, the act would isolate young women from all other possible supportive communities who might advise or help them to not have a child before they were ready. More than anything the law is about control. Not the reasonable control by which we as parents stop our children from touching a hot stove or running into the street, but a more insidious control by which we would force them to bear children when they're unwilling. A new generation of young women will have to live in the cage of this imposed choice for the rest of their lives. Their children will bear the burden of resentment. This new law now extends that cage throughout the country, and, by making criminals of those who would help, will require the rest of us to participate in maintaining it.

Paul Rogat Loeb is the author of The Impossible Will Take a Little While: A Citizen's Guide to Hope in a Time of Fear, winner of the 2005 Nautilus Award for the best book on social change, and Soul of a Citizen See To get his articles roughly once a month, email with the subject line: subscribe paulloeb-articles