Medicare chief Don Berwick, a Harvard professor widely respected for his ideas on how to improve the health care system, became the most prominent casualty of the political wars over a health care overhaul whose constitutionality will be now decided by the Supreme Court.
Praising Berwick for "outstanding work," White House deputy press secretary Jamie Smith criticized Republicans for "putting political interests above the best interests of the American people."
Berwick will be replaced by his principal deputy, Marilyn Tavenner, formerly Virginia's top health care official. The White House said Obama will submit Tavenner's nomination to the Senate.
Tavenner has been at Medicare since early last year, earning a reputation as a problem solver with years of real-world experience and an extensive network of industry contacts. A nurse by training, the 60-year-old Tavenner worked her way up to the senior executive ranks of a major hospital chain. She ran Virginia's health department under former Democratic Gov. Tim Kaine.
Berwick's fate was sealed early this year when 42 GOP senators -- more than enough to derail his confirmation -- asked Obama to withdraw his nomination. His resignation takes effect Dec. 2.
Berwick's statements as an academic praising Britain's government-run health care had become a source of controversy in politically polarized Washington. Although he later told Congress that "the American system needs its own solution" and Britain's shouldn't be copied here, his critics were not swayed.
In an email to his staff, Berwick said he leaves with "bittersweet emotions."
"Our work has been challenging, and the journey is not complete, but we are now well on our way to achieving a whole new level of security and quality for health care in America, helping not just the millions of Americans affected directly by our programs, but truly health care as a whole in our nation," Berwick wrote.
A pediatrician before becoming a Harvard professor, Berwick has many admirers in the medical community, including some former Republican administrators of Medicare. His self-styled "three-part aim" for the health care system includes providing a better overall experience for individual patients, improving the health of groups in the population such as seniors and African-Americans, and lowering costs through efficiency.
But some of his professorial ruminations dogged him in Washington. Republicans accused him of advocating health care rationing, which Berwick denies.
Sen. Orrin Hatch, R-Utah, said Berwick's past record of controversial statements and his lack of experience managing complex bureaucracies disqualified him from the Medicare job. Hatch, the ranking Republican on the Senate panel that oversees Medicare, led the opposition to his nomination. Hatch said Wednesday the Senate must "thoroughly examine" and "carefully scrutinize" Tavenner's nomination.
Berwick oversaw the drafting and rollout of major regulations that will begin to reshape the health care system, steering Medicare away from paying for sheer volume of services and procedures and instead putting a premium on quality care that keeps patients healthier and avoids costly hospitalizations. He also presided over significant improvements for Medicare beneficiaries, including better coverage for preventive care and relief for seniors with high prescription drug costs.
Berwick turned 65 this year, making him the first Medicare chief eligible to be enrolled in the program. He told The Associated Press in an earlier interview that he was putting in his application, but doesn't plan to retire any time soon. Instead he plans to keep working as an advocate for change in the nation's health care system.