From a Focus on the Family/Dobson press release:

It is an understatement to say that the pro-life community is disappointed by Sen. Frist’s decision to join efforts to void President Bush’s policy limiting the funding of embryonic stem-cell research. Most distressing is that, in making his announcement, Sen. Frist calls himself a defender of the sanctity of human life — even though the research he now advocates results, without exception, in the destruction of human life….
…The media have already begun speculating that Sen. Frist’s announcement today is designed to improve his chances of winning the White House in 2008 should he choose to run. If that is the case, he has gravely miscalculated. To push for the expansion of this suspect and unethical science will be rightly seen by America’s values voters as the worst kind of betrayal – choosing politics over principle.