Emily Lawrimore, a White House spokeswoman, said the surgeon general “is the leading voice for the health of all Americans.”

“It’s disappointing to us,” Ms. Lawrimore said, “if he failed to use this position to the fullest extent in advocating for policies he thought were in the best interests of the nation.”

Dr. Carmona is one of a growing list of present and former administration officials to charge that politics often trumped science within what had previously been largely nonpartisan government health and scientific agencies.

Dr. Carmona, 57, served as surgeon general for one four-year term, from 2002 to 2006, but was not asked to serve a second. Before being nominated, he was in the Army Special Forces, earned two purple hearts in the Vietnam War and was a trauma surgeon and leader of the Pima County, Ariz., SWAT team. He received a bachelor’s degree, in biology and chemistry, in 1976 and his M.D. in 1979, both from the University of California, San Francisco. He is now vice chairman of Canyon Ranch, a resort and residential development company.

His testimony comes two days before the Senate confirmation hearings of his designated successor, Dr. James W. Holsinger Jr. Two members of the Senate health committee have already declared their opposition to Dr. Holsinger’s nomination because of a 1991 report he wrote that concluded that homosexual sex was unnatural and unhealthy. Dr. Carmona’s testimony may further complicate Dr. Holsinger’s nomination.

In his testimony, Dr. Carmona said that at first he was so politically naïve that he had little idea how inappropriate the administration’s actions were. He eventually consulted six previous surgeons general, Republican and Democratic, and all agreed, he said, that he faced more political interference than they had.

On issue after issue, Dr. Carmona said, the administration made decisions about important public health issues based solely on political considerations, not scientific ones.