When a South Korean scientist took the lead in the stem-cell research race, U.S. lawmakers quickly moved to change the rules. Catching up with South Korea was so urgent that within days of Seoul's May 19 breakthrough announcement, Republicans and Democrats pulled pro-stem-cell legislation to the House floor. Lawmakers had expected a vote on the Stem Cell Research Enhancement Act, but not necessarily one that bypassed the committee where it had sat untouched for months.

"Where is the committee transcript that will tell us the diverse views of scientists on the potentiality of adult stem cells versus embryonic stem cells?" Rep. Marcy Kaptur (D-Ohio) asked during floor debate on the bill May 24. "I find it most coincidental that last week the South Koreans doing research in this area announced they had cloned cells, making it appear as though if Congress did not act today, Americans would fall behind in the world research community."

Many supporters of the bill confirmed they feared the United States might fall behind in scientific status.

"Our country has been a leader in so many areas of medicine," said Rep. Doris Matsui (D-Calif.). "Now is not the time to cede our role to countries like South Korea, Great Britain, and France."

House members crossed partisan lines to pass the act, 238-194, which would open federal funding to scientists who destroy leftover in vitro fertilization embryos for stem-cell research. The government currently only funds research on embryonic stem cells harvested before President Bush set up regulations in 2001. Scientists could receive funding under the new bill if the in vitro embryos they used would otherwise have been thrown away.

Doctors have treated more than 50 diseases such as leukemia and sickle-cell anemia with stem-cell transplants. In the transplants, adult stem cells act as factories for creating new, healthy cells that overcome the disease. Many scientists believe embryonic stem cells could similarly cure even more devastating diseases because, unlike specialized adult stem cells, they have the potential to produce almost all the tissue in a human body.

On May 19, a team led by Professor Hwang Woo-Suk of Seoul National University revealed a discovery that outpaced the rest of the scientific world. According to the journal Science, Mr. Hwang and his colleagues, "with speed and efficiency," engineered clones of adults and children with spinal cord injuries.

The way the research achieved speed and efficiency raises several ethical questions. The South Korean team made their embryos through cloning. They gave young, fertile women a hormone to increase their egg production. Then they harvested the eggs, removed their nuclei and implanted them with nuclei from sick patients' skin cells. The female donors received compensation for their travel expenses, but not for their eggs, researchers told Science. Still, the process raises questions about whether a scientific demand for young women's eggs could turn them into a commodity.

In Science, a U.S. bioethicist also questioned the study's use of child subjects, something American scientists generally avoid unless they are performing a clinical trial.

Shortly after the breakthrough research was announced, Mr. Bush promised to veto the Stem Cell Research Enhancement Act approved by the House. To override the veto, the bill's supporters would need 52 votes more than they collected to win passage on May 24.

Even if the act somehow survived to become law, the additional federal funding would not likely propel the United States to pass South Korea's new milestone. Federal funds remain off limits for research on cloned embryos, the centerpiece of the South Korean research.

During the House debate, Rep. Bart Stupak (D-Mich.) suggested the United States set a moral example for the rest of the world instead of trying to be scientific leaders in stem-cell research. House majority leader Tom DeLay (R-Tex.) whittled down the issue to one question: "What level of respect and dignity ought this government grant defenseless and unburdensome human life at its earliest stage?"

Across the country, politicians have attempted to answer that question, only to find themselves mired in the economic, technical, and emotional implications of embryonic stem-cell research. In 2005, more than 30 states considered bills about stem-cell research. As of the congressional vote on May 24, only two states had succeeded in codifying a policy on embryonic stem-cell research, according to the National Conference of State Legislatures.

In many states, stem-cell legislation failed because members did not vote along traditional party lines. In Missouri, embryonic stem-cell research had forceful supporters in Washington University and the Stowers Institute of Kansas City, both scientific powerhouses. They converted some traditionally pro-life Republicans by forecasting economic doom for the state if it banned research-related cloning. They also offered Republicans rhetoric to justify their pro-cloning stances.

Dr. Richard Chole is head of the otolaryngology department at the Washington University School of Medicine. In the months before Missouri's proposed cloning ban died in the General Assembly, Dr. Chole worked to explain the ethics and science of stem-cell research to politicians and the public. He met with Republican Gov. Matt Blunt, who had vowed to veto the cloning ban if it passed.

"The governor seems to differentiate between creating embryos through . . . cloning and the old-fashioned way. [Cloning] is not something that occurs by the fertilization of human egg and sperm, so the governor believes it is not a unique human being. It's identical to the genes in [the original] cell," Dr. Chole said.

Proponents of the cloning ban sought support by distinguishing the term "therapeutic cloning" from "reproductive cloning." Clones made for therapy, they said, could not develop into a full-term baby if implanted in a uterus.

But advances in "therapeutic cloning"-like those made in South Korea-create embryos that are more likely to develop in utero. Dr. Chole finds that possibility most threatening in the new research.

The Korean groups discovery, he said, "seems to indicate that some of the problems in cloning human embryos have been overcome by creating embryos which behave more like natural embryos. This advance may make their stem cells more suitable for transplantation, but they probably have greater potential for implantation and further embryonic and fetal development."

In cases like Mr. Hwang's, the difference between therapeutic and reproductive cloning could become a matter of ethics. The Korea Times described Mr. Hwang as a devout Buddhist whose beliefs helped him sort out the ethical questions of stem-cell research. The newspaper quoted one of Mr. Hwang's partners, Moon Shin-yong, as saying cloning represented a "different way of thinking about the cycle of life and rebirth."

Science reported that "Hwang and his colleagues had no intention of cloning a person."

Dr. Chole said today's embryonic stem-cell research climate tempts scientists who have the best intentions.

"Sometimes the potential for discovery is so overwhelming that scientists might compromise good ethical decisions," Dr. Chole said. "I think that they honestly feel that this is an avenue of discovery that is worth the . . . use of embryos."

That temptation is why scientists need an outside source of standards, Dr. Chole said. The standards set by the Stem Cell Research Enhancement Act still prevent federally funded scientists from experimenting with cloning.

As a researcher at a university that supports cloning for research purposes, Dr. Chole relies on his own set of standards.

"My perspective is that the Scripture is true," he said. "I think that's what Martin Luther King Jr.'s perspective was. Just as the fact that all people should have equal rights is a scriptural truth, the fact that we're designed and knitted together in our mother's womb not only is a scriptural truth, but it is a scientific truth as well."

A lifesaving alternative

A House vote to support adult stem-cell research was little more than a hiccup in news coverage of the embryonic stem-cell debate. But for a struggling network of private transplant banks across the country, the vote could turn out to be a lifesaver.

With a vote of 431-1, Congress appropriated more than $150 million over the next five years to support nationwide cord-blood stem-cell transplants. Until last week, Congress had appropriated no more than $30 million at a time to cord-blood transplantation.

"Cord-blood stem cells, collected from the placenta and umbilical cord after birth without doing harm to mother or child, have been used in the treatment of thousands of patients suffering from more than 60 different diseases," President Bush said in a statement supporting the measure. He urged votes on it as an alternative to the measure funding embryonic stem-cell research.

The bill's sponsor, Rep. Chris Smith (R-N.J.), compared the success of cord-blood transplants to the lack of treatments derived from embryonic stem-cell research.

"Umbilical cords are a rich, noncontroversial source of stem cells, but currently hospitals throw millions of them away each year because we do not have the infrastructure needed to properly collect and store them," Mr. Smith said. "The best-kept medical secret has been that thousands have been successfully treated with cord-blood stem cells for more than 67 diseases, including leukemia and sickle-cell anemia."

Cord-blood transplant doctors and banks have struggled since the close of a $30 million National Institutes of Health (NIH) cord-blood research grant program in 2001. That same year, Mr. Bush opened federal funding to embryonic stem-cell research. The federal Health Resources and Services Administration received $10 million in appropriations last year for collecting and banking umbilical cord blood.