But the battle of personification will assume a different and more sympathetic visage in the years to come. Perhaps the change in the weather was best illustrated when conservative Sen. Strom Thurmond invoked his own daughter to explain a position opposed by the anti-abortion forces. The senator’s daughter has diabetes. The actor Michael J. Fox has Parkinson’s disease. Christopher Reeve is in a wheelchair because of a spinal-cord injury, Ronald Reagan locked in his own devolving mind by Alzheimer’s. In the faces of the publicly and personally beloved lies enormous danger for the life-begins-at-conception lobby.

The catalytic issue is research on stem cells. These are versatile building blocks that may be coaxed into becoming any other cell type; they could therefore hold the key to endless mysteries of human biology, as well as someday help provide a cure for ailments as diverse as diabetes, Parkinson’s, spinal-cord degeneration and Alzheimer’s. By some estimates, more than 100 million Americans have diseases that scientists suspect could be affected by research on stem cells. Scientists hope that the astonishing potential of this research will persuade the federal government to help fund it and allow the National Institutes of Health to help oversee it. This is not political, researchers insist. It is about science, not abortion.

And they are correct. Stem-cell research is typically done by using frozen embryos left over from in vitro fertilization. If these embryos were placed in the womb, they might eventually implant, become a fetus, then a child. Unused, they are the earliest undifferentiated collection of cells made by the joining of the egg and sperm, no larger than the period at the end of this sentence. One of the oft-used slogans of the anti-abortion movement is “abortion stops a beating heart.” There is no heart in this pre-implantation embryo, but there are stem cells that, in the hands of scientists, might lead to extraordinary work affecting everything from cancer to heart disease.

All of which leaves the anti-abortion movement trying desperately to hold its hard line, and failing. Judie Brown of the American Life League can refer to these embryos as “the tiniest person,” and the National Right to Life organization can publish papers that refer to stem-cell research as the “destruction of life.” But ordinary people with family members losing their mobility or their grasp on reality will be able to be more thoughtful and reasonable about the issues involved.

The anti-abortion activists know this, because they have already seen the defections. Some senators have abandoned them to support fetal-tissue research, less promising than stem-cell work but still with significant potential for treating various ailments. Elected officials who had voted against abortion rights found themselves able to support procedures that used tissue from aborted fetuses; perhaps they were men who had fathers with heart disease, who had mothers with arthritis and whose hearts resonated with the possibilities for alleviating pain and prolonging life. Senator Thurmond was one, Senator McCain another. Former senator Connie Mack of Florida recently sent a letter to the president, who must decide the future role of the federal government in this area, describing himself “as a conservative pro-life now former member” of Congress, and adding that there “were those of us identified as such who supported embryonic stem-cell research.”

When a recent test of fetal tissue in patients with Parkinson’s had disastrous side effects, the National Right to Life Web site ran an almost gloating report: “horrific,” “rips to shreds,” “media cheerleaders,” “defy description.” The tone is a reflection of fear. It’s the fear that the use of fetal tissue to produce cures for debilitating ailments might somehow launder the process of terminating a pregnancy, a positive result from what many people still see as a negative act. And it’s the fear that thinking–really thinking–about the use of the earliest embryo for life-saving research might bring a certain long-overdue relativism to discussions of abortion across the board.

The majority of Americans have always been able to apply that relativism to these issues. They are more likely to accept early abortions than later ones. They are more tolerant of a single abortion under exigent circumstances than multiple abortions. Some who disapprove of abortion in theory have discovered that they can accept it in fact if a daughter or a girlfriend is pregnant.

And some who believe that life begins at conception may look into the vacant eyes of an adored parent with Alzheimer’s or picture a paralyzed child walking again, and take a closer look at what an embryo really is, at what stem-cell research really does, and then consider the true cost of a cure. That is what Senator Thurmond obviously did when he looked at his daughter and broke ranks with the true believers. It may be an oversimplification to say that real live loved ones trump the imagined unborn, that a cluster of undifferentiated cells due to be discarded anyway is a small price to pay for the health and welfare of millions. Or perhaps it is only a simple commonsensical truth.