WASHINGTON — The Senate early Friday approved the nomination of Representative Tom Price to be secretary of health and human services, putting him in charge of President Trump’s efforts to dismantle the Affordable Care Act.

By a vote of 52 to 47, the Senate confirmed Mr. Price, Republican of Georgia, after a debate that focused as much on his ethics and investments as on his views on health policy. Democrats denounced his desire to rein in the growth of Medicare and Medicaid by making fundamental changes to the programs, which insure more than 100 million Americans.

Senator Michael B. Enzi, Republican of Wyoming, said that Mr. Price, a 62-year-old orthopedic surgeon from the suburbs of Atlanta, was “one of the most capable, well-prepared individuals that President Trump could have chosen.”

“Who better than a doctor to head an organization that covers the wide variety of major health care programs?” Mr. Enzi asked.

The majority leader, Senator Mitch McConnell, Republican of Kentucky, said Mr. Price “knows more about health care policy than just about anyone.”

No senators crossed party lines on the roll-call vote, which ended after 2 a.m. on Friday.

Democrats said that Mr. Price, a House member since 2005, had shown bad judgment by actively trading shares of medical and pharmaceutical companies while shaping health policy in Congress. Mr. Price has denied wrongdoing and said at a confirmation hearing, “Everything that I did was ethical, aboveboard, legal and transparent.”

But he recently amended his financial disclosure statement to report a higher value for his investment in a small Australian biotechnology company, and Senator Patty Murray of Washington, the senior Democrat on the Senate health committee, said his financial dealings raised serious questions about potential insider trading that ought to be investigated by the Securities and Exchange Commission.

“While Congressman Price served on the powerful Ways and Means Committee, he traded in health care stocks, pushed policies that helped his portfolio and got special access to a promising stock deal,” said Senator Ron Wyden of Oregon, the senior Democrat on the Finance Committee.

Mr. Price will be the first physician to lead the Department of Health and Human Services since Dr. Louis W. Sullivan stepped down at the end of the first Bush administration in January 1993.

As secretary, Mr. Price will be responsible for a department with an annual budget of more than $1 trillion. Agencies within the department regulate food and drugs, sponsor much of the nation’s biomedical research and combat public health threats, including the Zika virus, opioid drug abuse and bioterrorism.

Some of the Democrats’ animus against Mr. Price stems from experience. Working with him over the last 12 years, they say, they have found him to be an effective advocate for conservative policies that they abhor.

“Buying and selling health care stocks as a member of Congress while you’re voting and helping those companies, that’s bad enough,” said Senator Sherrod Brown, Democrat of Ohio. “But what he wants to do to maybe the greatest program in American history, Medicare, is much, much worse.”

Senator John Cornyn of Texas, the No. 2 Senate Republican, said that Democrats were dragging their feet on confirming Mr. Trump’s nominees because of a desire to “block, stall and obstruct this president at every turn.”

Mr. Price has led efforts to repeal the Affordable Care Act and proposed a replacement plan that would roll back federal insurance standards and give states more authority.

“You could say his chief qualification for the job of replacing Obamacare is he had the good sense to oppose it in the first place,” said Senator Tom Cotton, Republican of Arkansas.

Democrats see it differently. “This is the first vote in the dismantling of the Affordable Care Act,” said Senator Maria Cantwell of Washington. Senator Jeanne Shaheen, Democrat of New Hampshire, said Mr. Price had been “a rabid supporter of defunding Planned Parenthood” and “seems to have no higher priority than to terminate health coverage for millions of people.”

As chairman of the House Budget Committee, Mr. Price supported proposals to shift Medicare away from its open-ended commitment to pay for medical services and toward a fixed government contribution for each beneficiary, which could be used for either private insurance or traditional Medicare. Such proposals could increase costs for some people.

The Senate Democratic leader, Chuck Schumer of New York, said Mr. Price had “dedicated his life to destroying Medicare as we know it.”

To make their case, Democrats highlighted a 2009 op-ed article in which Mr. Price said, “Nothing has had a greater negative effect on the delivery of health care than the federal government’s intrusion into medicine through Medicare.”

However, Mr. Trump, as a presidential candidate, often said he did not intend to cut Medicare.

Mr. Price has endorsed the idea of giving each state a fixed amount of federal money in the form of a block grant to provide health care to low-income people on Medicaid. That would be a radical change. Since its creation in 1965, Medicaid has been an open-ended entitlement. If more people become eligible, states receive more federal money.

Democrats have expressed outrage at many of Mr. Trump’s cabinet picks but have not mustered the votes to stop them.

Senator Orrin G. Hatch, Republican of Utah and chairman of the Finance Committee, said Democrats had smeared Mr. Price with “a vague patchwork of allegations of ethical impropriety.” He discerned a pattern: Democrats, he said, “have appeared to be apoplectic about almost every single nominee we’ve had before us.”

The Senate already had confirmed Mr. Trump’s nominees to lead six other departments — defense, education, homeland security, justice, state and transportation — as well as his picks for director of the Central Intelligence Agency and United Nations ambassador. After confirming Mr. Price, the Senate turned to the nomination of Steven T. Mnuchin, Mr. Trump’s pick to be Treasury secretary.

Senate confirmation is expected early next week for Mr. Mnuchin, a former hedge fund manager and Goldman Sachs executive who was national finance chairman for Mr. Trump’s presidential campaign.

But Mr. Mnuchin, like Mr. Price, has been criticized by Democrats, who boycotted a Finance Committee vote on his nomination. Mr. Mnuchin initially failed to disclose nearly $100 million of his assets to the committee, and he faced scrutiny over the foreclosure practices of the OneWest bank when he was its chairman.

SOURCE:NEWYORKTIMES