The U.S. Postal Service is facing an uncertain future after the resignation this week of Postmaster General Louis DeJoy and the suggestion by President Donald Trump and Elon Musk, who heads the Department of Government Efficiency, that the mail service could be privatized.

Unions representing postal workers have balked at the idea of privatization, staging protests across the country.

While they support modernization efforts, including those initiated by DeJoy, union leaders warned that allowing private corporations to run the U.S. mail will ultimately harm everyday citizens, especially the estimated 51 million people living in rural areas who depend on the Postal Service.

"It's a terrible idea for everyone that we serve," National Association of Letter Carriers President Brian L. Renfroe said during a panel discussion at the National Press Club in Washington, D.C., on Tuesday.

What happens next may depend on who becomes the next postmaster general. The U.S. Postal Service Board of Governors, an independent establishment of the executive branch that oversees the Postal Service, has retained a global consulting firm to conduct a search for the 76th postmaster general and CEO.

USPS currently employs about 640,000 workers tasked with making deliveries from inner cities to rural areas and even far-flung islands.

In February, Trump said he may put the U.S. Postal Service under the control of the Commerce Department in what would be an executive branch takeover of the agency, which has operated as an independent entity since 1970.

"We want to have a post office that works well and doesn't lose massive amounts of money," Trump said during the swearing-in ceremony for Commerce Secretary Howard Lutnick. "We're thinking about doing that. And it'll be a form of a merger, but it'll remain the Postal Service, and I think it'll operate a lot better."

While he didn't say anything about privatization at the event, the president has voiced support for the idea in the past. In December, he suggested privatizing the service given the competition it faces from Amazon, UPS, FedEx and others.

"It's an idea a lot of people have had for a long time. We're looking at it," the president said.

Musk, meanwhile, voiced support this month at a tech conference for privatizing the Postal Service, saying, "We should privatize anything that can reasonably be privatized," the New York Times reported.

Across the country, postal workers have been staging protests in recent days, many chanting "U.S. mail not for sale," and some holding signs that read: "The post office belongs to the people, not billionaires," a reference to Musk.

Renfroe said the goal of the protests is to make the American public aware that drastic changes are being considered for the Postal Service.

"Our message is: 'No.' Private business is interested in doing things that are profitable, as they should be," he said." But that is the distinction between private business and what we are, a public service, where we serve everyone, everywhere, no matter where they live, for the same price every day."

Since a reorganization in 1970, the USPS has been largely self-funded. The bulk of its annual $78.5 billion budget comes from customer fees, according to the Congressional Research Service. Congress provides a relatively small annual appropriation -- about $50 million in fiscal year 2023 -- to subsidize free and reduced-cost mail services.

Amid challenges that include the decline in profitable first-class mail and the cost of retiree benefits, the Postal Service accumulated $87 billion in losses from 2007 to 2020. However, the service reported a $144 million profit last quarter, attributing it to DeJoy's 10-year plan to modernize operations and stem losses. The service had reported a net loss of $2.1 billion for the same quarter last year.

"By steadily improving our product portfolio, we are increasing our competitive position in the shipping marketplace," DeJoy said in a written statement February accompanying the first quarter results for Fiscal Year 2025.

Union leaders said Wednesday that they hope the next postmaster general sticks with the modernization plan and considers harnessing the Postal Service to provide other services to the public, including basic banking, electric vehicle charging and even U.S. Census work.

"Our network of physical locations, retail locations ... our delivery network, puts us in a position to do so many different things," Renfroe said.