How serious are Republican — and some Democratic — politicians who go on and on about the need to restrict embryonic stem-cell research?

Not very.

Stem cell research, which scientists believe holds the promise of cures or treatments for everything from diabetes to Alzheimer’s disease, is popular with the American people. But it is unpopular with the faction of the anti-choice movement that tends to be most active in Republican primaries. So a lot of prominent Republican politicians tip their hat to the "pro-life" crowd by backing so-called "anti-cloning" bills that purport to restrict mad science but that are really written to prevent promising research projects from going forward.

The cloning critics seek to energize the faithful by backing these silly bills, while at the same time hoping that no one in the broader electorate will notice.

When the issue does become the fodder for a general election campaign, however, all best are off as, suddenly, stem-cell research critics become stem-cell research advocates.

That’s what has happened in Missouri, where Republican U.S. Senator Jim Talent has a long and ugly record as an outspoken advocate for the sort of restrictions on stem-cell research that are favored by the anti-choice movement.

Talent, who has never been a particularly popular senator, faces a tough challenge this year from Democrat Claire McCaskill, the very popular state auditor. McCaskill has actually been running ahead of Talent in some polls. She’s a supporter of stem-cell research, who is highlighting that stance in her campaign. "We should be promoting hope for people suffering with Alzheimer’s, Parkinson’s, diabetes, ALS, spinal cord injuries, and other debilitating diseases," said McCaskill, when she announced her support for a Missouri ballot initiative that seeks to guarantee that research into lifesaving cures can be done in the state.

"Stem cell research holds the promise of saving lives and alleviating the pain and suffering endured by so many of our people," added McCaskill. "This initiative enables Missouri doctors and researches to be at the forefront of lifesaving research and it has my support."

In a state where polls show voters favor embryonic stem-cell research by a 2-1 margin. Talent felt the heat. So, last week, he withdrew as a co-sponsor of a federal anti-cloning bill that that seeks to outlaw what many scientists see as one of the most promising forms of embryonic stem-cell research. Talent’s tortured speech announcing his new stance, in which he announced that he had come across "an ethically untroubling way" for obtaining embryonic stem cells that can be used in research, was an attempt to blunt McCaskill’s appeal. But, as McCaskill noted, Talent still supports many restrictions on stem-cell research.

"Unfortunately," McCaskill says of Talent, "like too many politicians, he’s trying to hide his opposition by dancing around science for politics. In a 30-minute long speech chock full of scientific jargon, he attempted to obfuscate his position and distract Missourians from the real issue: why does he think we should criminalize research instead of providing hope and cures for our people?"

McCaskill adds, with the directness that voters should expect of candidates on these issues: "I don’t need 30 minutes or even 30 seconds to tell you where I stand. I support hope, I support science, and I support lifesaving cures. Because desperately ill Missourians deserve hope, not political cover — and scientists deserve support, not handcuffs."