Stem cells are cells with the potential to grow into any
kind of tissue. Scientists say they present the possibility
of curing Parkinson's, Alzheimer's, diabetes, and other
diseases.But the most versatile stem cells, according to scientists, are harvested from unwanted human embryos -- the leftovers from embryos created in fertility clinics. Taking out the stem cells means destroying the embryo, and that, for many pro-life advocates, is murder.
One possible compromise reported under consideration: permit embryonic stem cell research with government funds, but only on cells harvested with private money.
As the president considers his choices, the lobbying has been intense, with some surprising alliances. Lucky Severson reports.
LUCKY SEVERSON: For those at the center of the battle over stem cell research, like Mary Jane Owen, it is often personal. She's suffered from blindness and other severe disabilities most of her life. And she says her doctors treated her as though her life had little value -- the same treatment, she says, most scientists afford embryos.
MARY
JANE OWEN (Executive Director, National Catholic Office
for Persons With Disabilities): I had to fire doctors because
they did not think that my quality of life was worth living.
So I want every potential person to have a chance to live
and fulfill their potential.SEVERSON: Another pro-life Catholic, former Florida Senator Connie Mack. He is a cancer survivor; so is his wife. But his brother died from it. He's in favor of stem cell research, because he thinks it may one day find a cure for diseases like cancer.
FORMER SENATOR CONNIE MACK: I believe that a person like myself who is called pro-life, which I am, and Catholic can come to the conclusion that the use of stem cells from embryos can fit within the values that I hold.
SEVERSON: Who would imagine the famous would become so involved in something so scientific. Again, it was personal -- searching for answers through stem cell research.
The fight over stem cell research is dividing a group which usually stands together -- pro-life conservatives who are coming down hard on opposite sides of the issue.
On
the one hand, you've got the likes of Senator Orrin Hatch
(pictured at right), himself no shrinking conservative,
who describes stem cell research as pro-life because it
could save millions of lives.

SEVERSON:
For example, why not use stem cells from adults? The president
is in favor of that, but many in the science community argue
that embryo stem cells offer far greater research possibilities.
They say this cluster of cells has the potential to grow
into muscle, blood, bone, and nearly every kind of tissue,
and possibly cure an assortment of diseases. The president
has said he would oppose federal funding for stem cell research
that involves destroying living human embryos. And that
gets back to the question of when does life begin.
FORMER
SENATOR MACK: Many people believe life begins at conception.
Most people believe though that conception is really the
fertilization of an egg in a uterus. They don't see it as
the fertilization of an egg in a petri dish or in a test
tube. And so, therefore, that's the way I in my own mind
can address that conflict, that struggle that I go through.