When Justin Trudeau became Canada’s prime minister in 2015, his relentless promise to improve life for the middle class resonated so strongly with Shivaan Burke that she went to work for the local Liberal member of Parliament, who was elected along with Mr. Trudeau.

But a decade later, as Mr. Trudeau prepares to leave office amid deep voter discontent, Ms. Burke said little of what he pledged has made its way into her family’s daily life in Peterborough, Ontario, a onetime factory town about 80 miles northeast of Toronto.

Like many Canadians, Ms. Burke has become painfully aware of how much of her budget is now consumed by trying to fill her grocery cart.

And while Peterborough used to be one place people in Toronto came to escape high real estate prices, housing costs have soared there in recent years, just as they have in many parts of the country.

Ms. Burke, a contract worker for the local government, is among the many middle class Canadians who helped propel Mr. Trudeau to power, but who have grown increasingly frustrated by a persistently high cost of living and incomes that have failed to keep up.

The latest version of a regular survey for the Royal Bank of Canada, the country’s largest financial institution, found that 55 percent of respondents “feel financially paralyzed due to rising costs.”

With national elections expected as soon as the spring, Mr. Trudeau’s Liberal Party is trailing the Conservative Party by at least 20 percentage points, according to recent polls. Pierre Poilievre, the Conservative leader, has relentlessly attacked Mr. Trudeau on inflation, referring to it as “Justinflation.”

The gains for the Conservatives have come in communities like Peterborough that once backed Mr. Trudeau but have now turned against him because of economic worries.

The result has been a precipitous fall for Mr. Trudeau, who announced this month that he would resign as Liberal Party leader and prime minister after his party selects his successor on March 9.

About a year after he took power, 73 percent of Canadians approved of his leadership, an exceptionally high figure for any Canadian politician. A survey taken this month shortly after Mr. Trudeau said he was on his way out found that only 19 percent of respondents viewed him favorably.

Peterborough was once known as the “Electric City” for its massive General Electric factory complex, which was largely shuttered in 2018 after 126 years of operation. Concerns about the cost of food and housing often dominate conversations both here and in the rest of Canada.

During a visit to Peterborough in 2017, Mr. Trudeau told a town hall that “the government should be helping you, not harming you.”

But during his tenure, many Canadians have only felt more pain financially.

Since Mr. Trudeau took office in 2015, average house prices have soared by 56 percent, with higher increases in larger cities like Toronto and Vancouver, with rippling effects in their surrounding suburbs. Homes in Peterborough surged by 132 percent since 2015.

One annual estimate compiled by food researchers and economists at four universities calculated that last year, a Canadian family of four spent 16,300 Canadian dollars, about $11,300, on groceries. That’s about 29 percent more than before Russia’s invasion of Ukraine in 2022, which set off price hikes worldwide.

“The groceries are just crazy, crazy — but I just accept it,” Alex Bierk, an artist and Peterborough City Council member, said at his studio in a downtown office building. “I feel powerless over it.”

He used to buy bags of pine nuts at Costco for about 10 Canadian dollars. “Now I see them and it’s a smaller version of the same bag and it’s something like 30 bucks.”

Incomes have not kept pace. Between 2016 and 2022, according to the most recent data available, average individual incomes in Canada rose only by 8 percent, to 57,100 Canadian dollars. That has also led to labor strife, including the shutdowns of Canada’s two major railways and the post office.

Ms. Burke said she was disappointed by Mr. Trudeau’s response to the struggles of the middle class.

“I am not sure how anybody, particularly any politician, can avoid drawing a line between the increase in the price of groceries and the increase in the profits being held by grocers,” she said. “We are seeing an increase in wealth disparity between the richest, most powerful people in this country and the rest of us.”

That sentiment was reflected in conversations in Peterborough, a city of about 130,000, that is frequently used to test new products because marketing research companies believe residents’ shopping habits reflect those of Canadian consumers in general.

On the south side of Peterborough, an area dominated by modest bungalows built for factory workers, Dan Twomey, 60, said he despairs about the rents his three daughters pay and their chances of ever becoming homeowners.

Mr. Twomey, who works for a fireplace store, said he and his wife bought their modest, three-bedroom house 25 years ago for 125,000 Canadian dollars. Before interest rates rose, cooling the market, he said he was offered about 750,000 dollars for it.

“This house isn’t worth that,” he said. Besides, to stay in Peterborough, he’d likely need to spend the same amount for a new, possibly smaller home.

While low interest rates and the pandemic, he said, contributed to the rise in house prices, Mr. Twomey also said that he believes Mr. Trudeau’s expansion of immigration — which saw more than two million migrants arrive in two years and which the prime minister now acknowledges went too far — was a major factor.

“We need immigration, we’re a pretty small country,” he said. “But we didn’t need that level of it.”

While the Trudeau government has managed to drive inflation down to about 2 percent from a high of 8 percent in 2022, food prices remain high.

And Canada’s economic situation could soon worsen significantly. President Trump said he plans to impose 25 percent tariffs on exports from Canada on Feb. 1. Such a blanket move could ravage Canada’s economy, lead to hundreds of thousands of job losses and push prices even higher as companies pass on the costs to customers.

Mr. Bierk, the Peterborough city councilor, said he was particularly frustrated by another manifestation of the country’s housing crisis: the growing number of homeless people, particularly those living in tent encampments.

Mr. Bierk worked with the city’s social housing agency to replace a tent camp downtown with 50 small modular houses placed around common washroom and eating areas and staffed with support workers. But funds for an additional 16 units, which must come through the provincial government, remain in limbo.

“The government,” he said, needed to make subsidized housing a priority “because every city in the country has an issue with encampments. And the problem just keeps getting worse as people get pushed into homelessness from the high cost of living.”

Jim Reedyk, the owner of Chumleighs, a used DVD, video game, CD and record shop on Peterborough’s main street, said that rising food prices had prompted him to scour grocery store ads for bargains for the first time in his life. He has also taken to offering local university students who come into the shop tips about cheaper grocery options, like discount stores.

He was once enthusiastic about Mr. Trudeau and what he might do for the country, but said he now feels disillusioned by his performance.

“I’m not saying he didn’t work hard and wasn’t dedicated to the people for many years,” Mr. Reedyk said. “I voted for the Liberals each time.”

But government policies, he added, are no longer working to help enough Canadians. “It was time for him to go,” Mr. Reedyk said.

The Trump administration has instructed organizations in other countries to stop disbursing H.I.V. medications purchased with U.S. aid, even if the drugs have already been obtained and are sitting in local clinics.

The directive is part of a broader freeze on foreign aid initiated last week. It includes the President’s Emergency Plan for AIDS Relief, the global health program started by George W. Bush that is credited with saving more than 25 million lives worldwide.

The administration had already moved to stop PEPFAR funding from moving to clinics, hospitals and other organizations in low-income countries.

Appointments are being canceled, and patients are being turned away from clinics, according to people with knowledge of the situation who feared retribution if they spoke publicly. Many people with H.I.V. are facing abrupt interruptions to their treatment.

But most federal officials are also under strict orders not to communicate with external partners, leading to confusion and anxiety, according to several people with knowledge of the situation.

U.S. officials have also been told to stop providing technical assistance to national ministries of health.

“The partners we collaborate with are in shock, and they do not know what to do because their lifesaving mission and commitment has been breached,” said Asia Russell, executive director of the advocacy group Health Gap.

Late on Sunday night, according to an email viewed by The New York Times, employees of the Centers for Disease Control and Prevention were instructed, effective immediately, to stop communicating with personnel at the World Health Organization.

They were later directed not even to be in the same meeting room — real or virtual — as W.H.O. employees or to participate in email conversations in which W.H.O. staff members are also engaged.

Some said they had been too afraid to contact colleagues they consider friends, even if just to say goodbye, and did not wish to be identified for fear of retribution.

On Monday afternoon, officials worldwide were alerted that PEPFAR’s data systems would shut down at 6 p.m. Eastern — roughly three hours after the email was received — immediately closing off access to all data sets, reports and analytical tools.

“Users should prioritize copying key documents and data,” said the email viewed by The Times.

The message prompted speculation that the program would not resume, as its future was already in question.

Some Republican senators have campaigned against PEPFAR’s reauthorization for five years, alleging that the program promoted abortions. In March, the program was renewed for one year.

Without treatment, virus levels in people with H.I.V. will quickly spike, hobbling the immune systems of the infected people and increasing the odds that they will spread the virus to others.

About one in three untreated pregnant women may pass the virus onto their babies.

Interrupted treatment may also lead to the emergence of resistant strains that can spread across the world.

One study estimated that if PEPFAR were to end, as many as 600,000 lives would be lost over the next decade in South Africa alone. And that nation relies on PEPFAR for only 20 percent of its H.I.V. budget. Some poorer countries are almost entirely dependent on the program.

“This is another domino in the devastating impact of the harmful freeze to programs, leaving lives hanging in the balance,” said Jirair Ratevosian, who served as chief of staff for PEPFAR during the Biden administration.