Arlen Specter's Stem Cell Battle

After 25 years in the Senate, Republican Arlen Specter of Pennsylvania is no stranger to political controversy. But lately, he says, he is a stranger to himself, reports CBS News Correspondent Gloria Borger.

"It's quite a shock to look in the mirror, Gloria, and not recognize yourself," he said.

That's because the senator is undergoing treatment for Hodgkin's lymphoma each weekend. Weekdays, he's back on the job.

"If I sit around and focus on all of these poisons they put into my system on chemotherapy, I might have time to feel sorry for myself," he said.

"As soon as I get to the office, as soon as I get to the committee room, as soon as I get to the floor -- I come alive and I feel fine."

Specter's latest fight is for embryonic stem cell research -- a longtime cause of his that has suddenly become very personal with the diagnosis of his own cancer.

"I can't help but think that if the war on cancer had been financed like the other wars, a cure could have been found for my ailment before I got it."

Specter argues that leftover embryos in fertility clinics should be made available for medical research funded by the government.

"The scientists know more than the people in the White House. And the scientists tell us they have enormous potential to cure diseases like the one I'm suffering from."

The president promises to veto Specter's stem cell measure if it passes, saying these embryos are alive, and that using them is taking one life to save another.

"You say it's a choice between something in a Petri dish and your life?" Borger asked.

"Life does not begin in a Petri dish. When people ask me the question when does life begin, I tell them -- I'm much more concerned about when life would end."

"Are you mad," asks Borger.

"You bet. I'm very angry that stem cells were not used in 1998 when we knew about them ... and I think it is scandalous when we have the potential to save lives and we're not doing so.

It's a fight Specter says he does not intend to lose.

"I think we have America on our side. For as long as I'm in the Senate or on the face of the earth, I intend to keep on fighting for it."