These days the most intense political battles over abortion are being fought on the periphery of the issue. There are no attempts at the moment to ban abortion by constitutional amendment or to overturn Roe v. Wade and send the matter back to the states. Rather, the current debates are about a ban on some late-term abortion procedures, which is now being challenged in court, and about a federal law making it a crime to cause the death of a fetus during an attack on a pregnant woman, which was passed by Congress last week.

In the debate over the Unborn Victims of Violence Act, which the Senate passed, 61-38, on Thursday, the prochoice side not only lost but also suffered some harm to its image.

The law, which makes the fetus a separate crime victim, applies only to federal crimes and is thus unlikely to result in many actual prosecutions, but it has great symbolic significance to both sides: for the first time, federal law gives the fetus the full legal status of a person.

The bill, also known as "Laci and Conner's Law" after California murder victim Laci Petersen and her unborn son, had widespread public support: Over 80 percent of Americans agree that if a pregnant woman is murdered or loses the child as a result of an assault, prosecutors should be able to bring separate murder charges for the death of the fetus.

When women's rights and prochoice groups opposed the law on the grounds that it would undermine the right to abortion (even though abortion is specifically exempted by the bill), their stance not only came across as callous but made them look like extreme ideological zealots.

Laws providing for murder or manslaughter charges for causing the death of a fetus already exist in 29 states, including Massachusetts, and so far they have not led to any encroachments on abortion rights. And yet concerns that the Unborn Victims of Violence Act is part of a strategy to chip away at abortion rights are not groundless.

The bill's supporters vigorously opposed an alternative bill proposed by Senator Dianne Feinstein, the California Democrat, which would have provided the same penalties for causing death or injury to the fetus during an attack on the pregnant woman, but without classifying the fetus as separate human being with full legal status.

In other words, the semantics matter. Today, the bill's prolife supporters may assert that it will not affect abortion rights; in the future, they may well use its logic to advocate a ban on abortion, arguing that it's absurd to make the personhood of the fetus contingent on whether the woman wants to go through with the pregnancy.

Nonetheless, the Feinstein bill (which was defeated, 51-49) was an easy target because it ignored the emotional resonance of the issue.

It's hard to argue against someone like Tracy Marciniak, a Wisconsin woman whose son died in her womb five days away from birth, during a savage beating inflicted by her husband. In her testimony before the House Judiciary subcommittee last summer, Marciniak produced a photo of herself holding her dead child at his funeral and asked, "Does it show one victim or two?" Marciniak also lashed out against a substitute "single victim" bill similar to Feinstein's.

Voting for that bill, she asserted, "would be saying to all of the future mothers, fathers, and grandparents who lose their unborn children in future federal crimes, `You didn't really lose a baby.' . . . Please don't tell me that my son was not a real murder victim."

Refusing to recognize a full-term unborn baby as a person is an extreme position that flies in the face of reality. But "Laci and Conner's Law" goes to the opposite extreme, recognizing the fetus as a person throughout the pregnancy and, at least in theory, enshrining the notion that life begins at conception.

The prochoice movement might have been able to avoid this debacle with a compromise solution: a bill recognizing the unborn child as a homicide victim after viability. (That, incidentally, is the law in Massachusetts; only 16 states make fetal homicide a crime from conception.)

For assaults that cause a miscarriage before viability, more severe penalties could apply without making the fetus a separate victim.

Why was such an option not even proposed?

Unfortunately, many abortion-rights supporters really are ideological zealots who oppose any restrictions on abortion any time in the pregnancy. Yet most Americans, including most who consider themselves prochoice, occupy a middle ground on the wrenching issue of abortion.

In this conflict, extremism is a ticket to defeat.