After more than 13 months of waiting, the Senate has come together in a bipartisan fashion and by a vote of 63-37, approved casting off the limits imposed by President Bush on stem-cell research.

But one last roadblock remains -- the threat by President Bush to veto this legislation -- the first veto of his presidency.

For the millions of Americans suffering from Parkinson's, diabetes, cancer and other illnesses that could one day be cured, this veto would be a crushing blow.

Anyone who has seen illness up close has to want cures, and stem-cell research offers the most promise. So I still have hope the president might change his mind and sign the bill. To do otherwise would leave a harsh legacy for his presidency.

The legislation approved by the Senate -- championed by Reps. Michael Castle, R-Del., and Diana DeGette, D-Colo. -- is remarkably straightforward: It reverses the policy announced by the president in 2001, when he restricted federal funding to stem-cell lines already in existence. This would allow American researchers to once again explore the promise of this bright new frontier of research.

The president himself acknowledged the great promise of stem cells back in 2001. True support for stem cells means lifting the restrictions from hampering some of the most promising research, and only the Castle-DeGette bill will do that.

Today, the few available stem-cell lines are worthless because they are all contaminated with mouse feeder cells and cannot be used for human research.

The Castle-DeGette legislation now approved by both the House and the Senate would make available for use stem-cell lines derived from embryos left over from in vitro fertilization clinics -- embryos that are already slated to be disposed of and, therefore, it is difficult to understand the objections.

Also, the ethical parameters created by this legislation are numerous and strict:
  • The embryos must be left over after fertility treatment.
  • It must be clear that the embryos will be discarded.
  • The people donating the embryos must provide written consent.
  • These donors may not be compensated for their donation.

These restrictions mean that more than 400,000 embryos could become available, all while ensuring that researchers meet the highest of ethical standards.

Let us be clear: We are talking about embryos that will be destroyed, whether or not this bill becomes law. It is an indisputable fact these embryos have no future.

I can think of nothing more ethical than using embryos that would otherwise be wasted, to generate new, viable stem-cell lines offering medical hope and promise to so many.

We cannot forget that this debate is about real people, whose lives are affected by illness every day.

There is still much that we do not understand about stem cells; some of these cures may never come to fruition. But unless we allow our scientists to continue their work, we simply will not know. In fact, because of President Bush's current restrictive policy, some of our best and brightest scientists are leaving the United States to work overseas in countries that have embraced the promise of comprehensive stem-cell research.

Researchers are attracted by the federal funding provided in at least 10 other nations -- Germany, Finland, France, Sweden, United Kingdom, South Korea, Singapore, Israel, China and Australia.

American scientists, on the other hand, cannot obtain federal funding to do this work.

Meanwhile, several states, including California, are launching exciting initiatives to fund the research the federal government is ignoring.

But a patchwork, state-by-state approach is no way to run science policy. States have many other responsibilities, like funding education and building infrastructure. We should not expect them to solely carry the burden of funding one of the most promising fields in science. The federal government is a leader in so many other kinds of science. Stem-cell research should be no different.

No matter what action the president takes, the need for stem-cell research will not go away. And my colleagues and I will not stop fighting for this. We will continue to push in every way possible. Patients suffering from these catastrophic illnesses have already waited too long.