By Will Dunham WASHINGTON, July 11 (Reuters) - A leading public health group opposed President George W. Bush's surgeon general nominee on Wednesday, a day before Dr. James Holsinger, already under fire by Democrats and gay rights groups, faces a tough Senate confirmation hearing. The American Public Health Association, founded in 1872 and made up of 50,000 U.S. public health professionals, said it is "very concerned with Dr. Holsinger's past writings regarding his views of homosexuality, which put his political and religious ideology before established medical science." It was the second time ever, and the first in 26 years, that the group has opposed a U.S. surgeon general nominee. The Human Rights Campaign, the National Gay and Lesbian Task Force and other groups have opposed Holsinger's nomination to be the nation's top doctor, citing in part a document he wrote in 1991 titled "Pathophysiology of Male Homosexuality." Written to a United Methodist Church panel studying homosexuality, Holsinger described anal sex as unnatural, offering an expansive anatomical explanation. Some prominent Democrats, including presidential hopefuls Illinois Sen. Barack Obama and former North Carolina Sen. John Edwards, also have criticized what they called Holsinger's "anti-gay" statements. "At a time when one of our association's top priorities is to eliminate disparities in health, including disparities in the gay and lesbian community, we cannot support a nominee with discredited and non-evidence-based views on sexuality," APHA Executive Director Dr. Georges Benjamin said in a letter to the leaders of the Senate Health, Education, Labor and Pensions Committee, which will hold a confirmation hearing on Thursday. 'TOO EARLY TO COUNT THE NUMBERS' - WHITE HOUSE The HIV Medical Association, whose members are 3,600 doctors, researchers and other health care professionals in the AIDS field, opposed Holsinger on similar grounds on Monday. Surgeons general educate the public about pressing health issues, and in the past have issued influential reports on subjects like smoking, AIDS and mental health. Emily Lawrimore, a White House spokeswoman, called it premature to predict whether Holsinger will win confirmation. "I think it's a little too early to count the numbers right now, but we are confident that as members of the Senate, members of the committee, learn more about his experience and clear commitment to caring for all Americans, they will be impressed," Lawrimore said. Bush nominated Holsinger on May 24, saying he would focus on childhood obesity. He was nominated to succeed Dr. Richard Carmona, who finished his term last year with no replacement. In congressional testimony on Tuesday, Carmona accused the Bush administration of political interference and muzzling him on key issues including embryonic stem cell research. "If you're the voice of the nation on health care, and you feel it's important enough, then you have an obligation to speak about it," White House spokesman Tony Fratto said. But Matt Foreman of the National Gay and Lesbian Task Force said, "The Bush administration not only expects, but demands, that right-wing ideology and partisan politics triumph over science and they know Dr. Holsinger will compliantly deliver." Holsinger, a cardiologist, has served as Kentucky state health chief and University of Kentucky Medical Center chancellor. He served more than 30 years in the Army Reserve. Gay rights groups also faulted his actions as a senior United Methodist Church official opposing lesbian ministers. Sen. Edward Kennedy, chairman of the committee that will hear from Holsinger, has said he is disappointed Bush "chose an individual whose record appears to guarantee a polarizing and divisive nomination process."