was Frist gaming the religious right?
It has been my position for some time that neither Bush nor much of the Republican leadership really believe what they say about stem cells. Bush's original rule was that federal funds could go to research using existing stem cell lines, but not new ones. He said that for the existing lines "the life or death decision has already been made." At the time, I argued that this statement showed that Bush did not really respect embryos as persons with rights, because one would never make such a statement about, say, corrupting a mass grave. If he were staying consistent with his principles, Bush would have either banned all stem-cell research or offered the alternative justification that such research encourages abortion (which is the reason why I personally think there should be strict guidelines for the research, as there are with organ donation and similar procedures).
Frist basically admits the contradiction in his position when he says: "I am pro-life. ... I believe human life begins at conception. ... I also believe that embryonic stem cell research should be encouraged and supported." (To be fair, Kerry made similarly vexing statements, but no one is chanting "flip flop flip flop" at Frist.) I'm guessing what Frist actually believes is that life begins *shortly after* conception, since the ethical problems posed by sacrificing a life for the sake of research are obvious (particularly for doctors). He explains the apparent change in his position by saying that the stem cell lines left available by Bush are not sufficient for research -- but this poses similar problems.
This is all besides the point though. The real question is why Frist decided to change his position now. The point about the number of lines seems like a sham -- people tend to have a fundamental passion for or against stem cell research, just as they do with abortion. Frist's statement is not cautionary -- it seems clear that he has always been sympathetic with the idea of using stem cells in experiments. So why come out in favor of them now.
My guess is that when the stem-cell debate re-emerged after the election, Frist wanted to be in favor of research, but knew he might lose support with the religious right. So, to gain credibility with them, he attempted to gain as much media attention as possible for his stances on two other issues of importance to the religious right -- the Terri Schiavo case and Bush's federal circuit court nominees (which, one could argue, was not considered a religious issue before Frist helped make it one). Now it would be hard to avoid attention on these issues for the Senate majority leader. But Frist deliberately went out of his way to draw attention to his stance on these topics by doing things like making a medical judgment based on a video tape and touting the "nuclear option" in the Senate. Perhaps Frist knew that he would need to vote in favor of stem cell research in the future, and wanted to raise sufficient political capital with the religious right so he could avoid being punished when he did.
That's just my theory. Any further speculation either way would be welcome.