Sen. Arlen Specter

A U.S. Senator and cancer sufferer says countless lives could be saved if the United States expanded medical research involving embryonic stem cells. President Bush has threatened to veto a bill that would broaden federal support for the controversial area of study.

Pennsylvania Senator Arlen Specter is a Republican ally of President Bush on Capitol Hill, but a political moderate and notoriously independent-thinker. That independence is once again on display. Senator Specter, who was diagnosed with lymphatic cancer [Hodgkin's lymphoma] earlier this year, is a passionate advocate of expanded embryonic stem cell research that President Bush opposes.

"We have 110-million people in this country who are directly affected by illnesses, or their families are, who have the potential to have their lives saved if we do not tie the hands of medical research," said Mr. Specter, speaking on ABC's "This Week" program. "So we have two choices: one is we use these embryonic stem cells to save lives, or we throw them away."

The stem cells in question come from embryos that, were they to be carried to term in a womb, could develop into healthy human babies. But the embryos at the heart of the controversy are stored at fertility clinics. U.S. clinics discard hundreds of thousands of "surplus" embryos every year.

Scientists say stem cells extracted from embryos show great promise for one day curing a wide variety of illnesses and debilitating conditions. But Kansas Republican Senator Sam Brownback echoed President Bush's view that human life should not be destroyed to save human life, and urged harvesting stem cells from adults and other non-embryonic sources.

"These are human lives. When did each of your lives begin? When did your life biologically start? And we should not be researching on that life at any time during the continuum unless we have your consent," he said.

"I am a lot more concerned at this point about when my life is going to end," responded Senator Specter bluntly.

Last week, the House of Representatives passed a bill expanding federal funding for embryonic stem cell research. Backing for the bill fell short of the two-thirds that would be required to override a presidential veto. The Senate has yet to vote on the matter.

Debate on the issue extends beyond the federal level to individual U.S. states, several of which have enacted their own measures in support of stem cell research.