There may not be a Donald Trump Cabinet pick who would touch more lives than U.S. Rep. Tom Price, a Georgia Republican who was nominated Tuesday as U.S. health and human services secretary.

The former orthopedic surgeon and current chairman of the House Budget Committee has helped lead the charge to repeal the Affordable Care Act, and he supports major changes in programs that cover the elderly and the poor.

Price's nomination as HHS secretary is seen as a clear signal that Trump plans to make good on his campaign pledge to repeal Obamacare.

That’s a major disappointment for Harvard T.H. Chan School of Public Health professor John McDonough and others who have worked on health care reform for decades.

"Massachusetts has prided itself for over a decade now in being the state that has reduced the number of people without health insurance to the lowest ever seen in the history of the country," McDonough said, "and the legacy of that is now at risk."

Some health care leaders have said, hold on, Massachusetts will find a way to make sure 97 percent of residents keep their coverage.

But Price has a plan to replace Obamacare, and it includes many changes that would make that difficult.

Price has proposed rolling back Obamacare's Medicaid expansion, through which more than 300,000 Massachusetts residents now receive health insurance. Price proposes new limits on tax breaks for employers, reducing a company’s incentive to provide coverage.

McDonough says Massachusetts could never have launched the state’s health coverage law without major federal funding and support.

"Right now, we don’t know," McDonough said, "and we have reason to be concerned about how much of a partner that federal government will want to be over the next four years with Massachusetts."

Though Joshua Archambault, a senior fellow at the Pioneer Institute, says the proposed changes would force the state to pay more attention to the real problem: how to cut health care costs.

"For Massachusetts this change should force some important conversations about our insurance market, transparency of health care prices and our heavy dependence on federal tax dollars to keep our health coverage system afloat," Archambault wrote in an email. "When states have to spend more state budget dollars to pay for coverage instead of on education or public safety, the conversation changes significantly."

But Brandeis health policy professor Stuart Altman says it may also be time for Massachusetts to prepare a backup plan in case the ACA goes away.

"Unless we in Massachusetts put in place something that is independent of that, it’s going to be a problem," Altman said.

Price would have an ally for his plans in Republican House Speaker Paul Ryan. In addition to repealing the ACA, both support making Medicare, which covers 57 million seniors and those with disabilities, a private system Americans would buy into with vouchers.

Altman, who worked in Washington for decades going back to the Nixon administration, says Price and Ryan would face strong opposition to the Medicare plan in the Senate.

"I think some of the more extreme aspects of that plan are going to be modified, if not shelved," he said.

Some women’s groups worry Price would roll back reproductive rights.

Christian Miron, with the advocacy group NARAL Pro-Choice Massachusetts, says Price has voted to ban abortion in some cases and limit birth control coverage through the ACA.

"Particularly the contraceptive coverage mandate," Miron said, "through which millions of women across the country and here in Massachusetts are able to access birth control of their choosing."

Overall, Price is expected to push for a smaller federal government, and there would be many places where he could shrink the role federal agents play. At HHS, Price would oversee the FDA, the Centers for Disease Control and Prevention and agencies that fund medical research.

Some physicians and hospital administrators in Massachusetts say they are hopeful that Price, a veteran doctor, understands the complexity of the vast agency he seeks approval to lead.