In his statement, McCain at first claimed to support ESC research. However, he said "clear lines should be drawn that reflect a refusal to sacrifice moral values and ethical principles for the sake of scientific progress" -- a qualification that disturbed many scientists and bioethicists with its ambiguity.

McCain also took a harder line than the Bush administration with somatic cell nuclear transfer, better known as therapeutic cloning -- a cutting-edge process that could some day provide personalized embryonic stem cell therapies. Though currently legal, McCain would outlaw the technique.

The new stance is an abrupt reversal for the Arizona senator. As recently as 2007, McCain appeared to favor embryonic stem cell research more strongly than most of the Republican party, especially its most religiously conservative members. "I believe that we need to fund this," he said during a presidential candidates' debate in May 2007.

Since then, he's become steadily cagier in his support, courting Kansas Sen. Sam Brownback, an ardent opponent of all ESC research, and avoiding discussion of ESCs in favor of alternative cell types. Those familiar with the debate interpreted McCain's latest platform, which framed his support in the language of research opponents, as a signal that President Bush's research-limiting policies may continue.

"I am researching SCNT and so would be considered a criminal if McCain gets his way," said the Harvard researcher Daley. "It's a sad society that starts criminalizing legitimate science."

The administration, Carmona said Tuesday, would not allow him to speak or issue reports on the subjects of stem cells, emergency contraception, sex education or prison, mental or global health issues. Top officials tried to "water down" a landmark report on secondhand smoke and delayed it for years, he said. Released last year, the report concluded that even brief exposure to cigarette smoke can cause immediate harm.

Carmona said he was ordered to mention President George W. Bush three times on every page of his speeches. He also said he was asked to make speeches to support Republican political candidates and to attend political briefings.

Administration officials even discouraged him from attending the Special Olympics because, he said, of that charitable organization's longtime ties to a "prominent family" that he declined to name. "I was specifically told by a senior person, 'Why would you want to help those people?' " Carmona said.

The Special Olympics is one of the nation's premier charitable organizations to benefit disabled people, and the Kennedy family has long been deeply involved in it. When asked after the hearing whether that "prominent family" was the Kennedys, Carmona responded, "You said it. I didn't."

Polls consistently show that a majority of Americans want federal funding for stem cell research and they want it now, not later. But President Bush appears determined to make sure that America falls behind the rest of the world in scientific advances. Japan, for one, is already way ahead of us on this issue which could potentially provide a cure for diabetes, some cancers, Parkinson's and Alzheimer's.