WASHINGTON — Republicans pushed U.S. surgeon general nominee Vivek Murthy on Tuesday to address whether his support for gun control and the new health care law would affect his objectivity if he becomes the nation’s top doctor during a Senate confirmation hearing.

Murthy co-founded the liberal organization Doctors for America, which was originally established in 2008 as Doctors for Obama and is closely aligned with the president’s health care plan. At the hearing several senators expressed concern over Murthy’s tweets calling for increased gun control and supporting the new health care law.

During Tuesday’s confirmation hearing before the Senate Health, Education, Labor and Pensions Committee, Sen. Lamar Alexander, R-Tenn., asked Murthy if he would use the position of surgeon general as a “bully pulpit” for his support for gun control, and Sen. Tim Scott, R-S.C., characterized him as having had “unprecedented involvement in partisan politics.”

“If you’re appointed surgeon general, do you feel that you’d be capable of advocating positions that are perhaps inconsistent with the administration’s position on health care?” Scott asked. “How would you balance what seems to be a very partisan stripe with being very objective when it comes to meeting those health care needs of patients?”

Murthy said his opinions were grounded in medical expertise and his experience as a physician, adding that he believed the surgeon general should unite groups of “all political stripes.”

“My work is motivated primarily by one thing, and that’s to improve the health in communities,” Murthy said. “I recognize that the role is not to be a legislator or a judge. The role is to be a public health educator.”

The committee also questioned Murthy about his stance on contraception coverage provided under the Affordable Care Act and doctor-prescribed marijuana. Murthy expressed support for access to contraception but said more research is needed on the effects of medical marijuana.

Committee Chairman Tom Harkin, D-Iowa, and Sen. Elizabeth Warren, D-Mass., praised Murthy’s record as a physician, including his membership on the Advisory Group of the National Prevention Council since 2011 and work on HIV prevention in India. Harkin called Murthy “exceptionally well-qualified” and “an active participant in the campaign to transform America’s traditional ‘sick care’ system into a genuine health care system.”

At 36 years old, Murthy would become one of the youngest surgeon generals in history if confirmed. He is an attending physician at Brigham and Women’s Hospital and a Harvard Medical School instructor. He also co-founded the medical organizations TrialNetworks and VISIONS Worldwide.

During his statement to the committee, Murthy identified obesity, health care prevention and building community partnerships as his top priorities, along with strengthening medical research. He also pledged to collaborate with numerous federal agencies to make health care a priority across all facets of government.

“We have to work with communities to translate information into action,” Murthy said.

The surgeon general oversees the U.S. Public Health Service Commissioned Corps and leads the National Prevention Council, which develops national health prevention and promotion initiatives. The previous surgeon general, Regina Benjamin, is known for championing suicide prevention initiatives and working to reduce heart attacks.

Murthy will face a full Senate vote if the HELP committee acts favorably on his nomination.