Delivering a slap to his late father's political party, Ron Reagan (search) told Democratic delegates Tuesday that voters in November face a choice between "the future and the past, between reason and ignorance, between true compassion and mere ideology," on the matter of embryonic stem cell research.

"I am here tonight to talk about the issue of research into what may be the greatest medical breakthroughs in our or in any lifetime -- the use of embryonic stem cells, cells created using the material of our own bodies -- to cure a wide range of fatal and debilitating diseases," Reagan said in an address to the Democratic National Convention (search).

Reagan, 46, became an active supporter of stem cell research after his father, President Reagan, was diagnosed with Alzheimer's disease (search). The elder Reagan died of complications of the disease last month at age 93. Nancy Reagan (search) also is a strong advocate of stem cell research.

Scientists believe stem cells, the body's building blocks, can be used to repair organs or treat diseases such as diabetes, Parkinson's and Alzheimer's. But because stem cells are typically removed from days-old human embryos that are later destroyed when the cells are extracted, many anti-abortion activists oppose such research.

President Bush has ordered sharp restrictions on federal funding of embryonic stem cell research, allowing it only for stem cells created before Aug. 9, 2001.

Reagan, a television journalist and longtime liberal activist, insisted that his speech was not intended to be political and that the issue of stem cell research should never be partisan. But his criticism of Bush and other stem cell research opponents was clear.

"It does not follow that the theology of a few should be allowed to forestall the health and well-being of the many," Reagan said. "And how can we affirm life if we abandon those whose own lives are so desperately at risk?"

And while acknowledging some opponents of the research truly believe that an embryo at its earliest stages is an actual fetus, "a few of those folks ... are just grinding a political ax and should be ashamed of themselves."

Reagan devoted much of his speech to describing a 13-year old friend who suffers from juvenile diabetes, saying she faces an uncertain future.

"What excuse will we offer this young woman should we fail her now?" Reagan asked. "That facing political opposition, we did nothing? That even though we knew better, we did nothing?"