Seizing an issue with overwhelming bipartisan support, the Kerry campaign is marking the third anniversary of President Bush's decision to limit federal embryonic stem cell research with a series of high-profile events this week that call into question the administration's commitment to science and breakthrough medicine.

Sen. John F. Kerry (Mass.), building on a theme he and Ronald Prescott Reagan introduced at the Democratic National Convention, launched the latest attack yesterday in the weekly Democratic radio address, pledging that when he takes office the Bush restrictions will be lifted and he will "stand up for science."

Tomorrow, daughter Vanessa Kerry, running mate Sen. John Edwards (N.C.), doctors, patients and scientists will hold briefings, rallies and news conferences to highlight an issue on which they say Bush is far from the mainstream.

"For families and for patients, too many of us have anniversaries we have to mark, whether it's the anniversary of an accident or a death or date of diagnosis," said David Carmel, who left his private sector job to coordinate medical research outreach for Kerry. "We hope to make Aug. 9 the last anniversary of federal restrictions on stem cell research."

Though they are not working with the Kerry team, several nonpartisan organizations will reinforce the Democrat's message. Former attorney general Janet Reno, who has Parkinson's disease, will join a rally sponsored by the Genetics Policy Institute in Miami, while the New York-based Committee for the Advancement of Stem Cell Research is running radio ads that warn that a vote for Ralph Nader means "four more years of delays," co-founder Frank Cocozzelli said.

Rarely has a technical scientific matter rated such prominence in a presidential contest. But pollsters on both sides say that in a close race in which the electorate is so polarized, stem cell research -- or, more broadly, science and medicine -- may be one of the few topics with the power to lure independents and moderates to the Democratic ticket.

"This is an issue with legs," said Democratic pollster Peter Hart, who has measured 70 percent support nationwide for embryonic stem cell research. He predicted that Kerry will attract support from disease sufferers and families who otherwise agree with Bush on public policy but feel "alienated" by his decision to restrict federal funding for embryonic stem cell research.

On Aug. 9, 2001, Bush chose stem cell research as the topic for his first prime-time televised address, announcing that he would permit tax dollars to be spent only on research involving embryonic stem cells that existed at that time.

"Embryonic stem cell research offers both great promise and great peril, so I have decided we must proceed with great care," he said. "This allows us to explore the promise and potential of stem cell research without crossing a fundamental moral line by providing taxpayer funding that would sanction or encourage further destruction of human embryos that have at least the potential for life."

Scientists are eager to study the primitive cells extracted from 5-day-old embryos because they have the rare ability to morph into virtually any type of human tissue. That could pave the way to treat patients with "replicated" tissue cells in situations such as spinal cord injuries, Parkinson's and juvenile diabetes.

Opponents, including antiabortion activists and some religious leaders, object because the work involves the destruction of an embryo. They advocate research on adult or fetal tissue stem cells instead.

Now, three years after administration officials claimed they would make 78 cell lines and $100 million a year available for the controversial research, scientists and patient groups complain that the Bush policy is inadequate. Fewer than two dozen cell lines are available, and the budget for embryonic stem cell studies is $25 million.

"Here in America, we don't sacrifice science for ideology," Kerry said in his radio address. "Every day that we wait, more than 3,000 Americans lose their lives to diseases that may someday be treatable because of stem cell research."

Bush allies point out that there are no limits on privately funded embryonic stem cell research and say an expansion of the federal program would probably mean taking money from other scientific work.

The August 2001 announcement was "not a decision based solely on science but on the health care, ethical and legal landscape of embryo protection in this country," former Bush domestic policy adviser Jay Lefkowitz said in a recent interview. "The president isn't just taking a look at the science. If all we did was focus on the science, we would harvest the organs of people who are terminally ill or people on death row."

On a fact sheet titled "Embryonic Stem Cell Research," the administration reports that about $208 million has been spent on private research. That figure, however, is for all types of stem cell research, not just embryonic cells.

In a typical campaign year, it would be hard to imagine stem cells as a burning issue, said G. Terry Madonna, director of the Center for Politics and Public Affairs at Franklin & Marshall College in Lancaster, Pa. But this year, the two campaigns are searching for anything that could win over even a small number of undecided voters.

"Voters are not going to fully appreciate in a short campaign the complexity of the medical and biological implications of this," Madonna said. "But what is important is if Kerry can frame this as the Bush people opposing science, opposing medicine, hurting people who have a chance to live longer or cure diseases."

Unlike her son Ronald, Nancy Reagan has endorsed Bush despite their differences on embryonic stem cell research funding, a reminder that even though 70 percent of the public supports the research, Kerry cannot count on all their votes.

As a result, the Kerry team aims to broaden its pitch by arguing that Bush has chosen ideology over science.

Members of the recently formed Scientists and Engineers for Kerry intend to tour college campuses and research institutions making the case that it is in their interest to work on behalf of the Democratic ticket.

Tomorrow, prominent scientists, several patients and Rep. Tammy Baldwin (D-Wis.) will critique the Bush policy; on Tuesday, members of Doctors for Kerry will appear in New Hampshire with former governor Jeanne Shaheen to highlight the medical promise of embryonic stem cells.