As he heads toward a re-election campaign next year, President Biden is betting that his success in pushing for policies intended to lower health care costs for millions of Americans will be rewarded by voters at the ballot box.

In speech after speech, Mr. Biden talks about capping the cost of insulin at $35, putting new limits on medical expenses for seniors, making some vaccines free and pushing to lower the prices of some of the most expensive drugs in the world.

At the White House, Mr. Biden and his advisers have already begun to elevate the issue as a centerpiece of his agenda. And at his campaign headquarters in Wilmington, Del., aides are preparing television ads, talking points and speeches arguing that Mr. Biden’s push for lower health care costs is a stark contrast with his Republican opponents.

“The president will have a very strong case to make,” said Senator Amy Klobuchar of Minnesota, a member of the president’s national campaign advisory board. “Not only will people want to keep the benefits they have seen, they are going to want to get the benefits that are coming their way.”

On Tuesday, the White House announced that the Biden administration will negotiate on behalf of Medicare recipients for lower prices on 10 popular — and expensive — drugs that are used to treat diabetes, heart disease and other chronic illnesses.

The move was made possible by passage last year of Mr. Biden’s Inflation Reduction Act, which for the first time allows Medicare to negotiate drug prices for older adults, a change that has been opposed by the pharmaceutical industry for decades.

Republicans also generally oppose giving the government the right to negotiate drug prices. But the candidates for the Republican presidential nomination have said little about the cost of medication, focusing instead on abortion, transgender medical issues and Covid lockdowns.

In his speeches, Mr. Biden rails against the industry and his Republican adversaries in Congress, all of whom voted against the law that included the prescription drug provisions. Aides say it is an effective message.

“Today is the start of a new deal for patients where Big Pharma doesn’t just get a blank check at your expense,” the president said at a White House event celebrating the change.

Since signing the law a year ago, Mr. Biden has repeatedly called it one of his proudest legislative victories. But his approval numbers have hardly budged. And while polls show that the new policy is widely popular among Americans who know about it, they also suggest that far fewer people are even aware that the change was made.

That is most likely because prices on just the first handful of drugs are not scheduled to actually drop until 2026 at the earliest, assuming Mr. Biden’s program survives legal challenges. Drug companies have filed numerous lawsuits against the administration that claim the law is unconstitutional. Court cases could drag on for years.

In its lawsuit against the administration, the Pharmaceutical Research and Manufacturers of America, an industry trade group, called the plan for negotiated prices “a government mandate disguised as negotiation.”

Even if Mr. Biden’s plan goes into effect, older adults who have made the choice to ration their drugs will have to continue doing so until more than a year after the 2024 presidential election.

Danny Cottrell, 67, a pharmacist who owns his retail pharmacy group in Brewton, Ala., said he regularly advised his Medicare patients on the ins and outs of the government’s prescription program. He welcomed Mr. Biden’s changes, but said it would be up to people like him to explain the complicated process.

“I got to remind them, this doesn’t start till 2026,” Mr. Cottrell said. “And then also remind them this thing will change several times between now and then.”

Neera Tanden, Mr. Biden’s top domestic policy adviser, said the White House was confident that the plan would survive the legal challenges.

“It is absurd to argue that negotiation is unconstitutional,” she said in an interview. “There’s nothing in the Constitution that says Medicare negotiating drug prices is unconstitutional.”

But more broadly, Ms. Tanden said that she and the president’s other advisers in the West Wing were determined to make the push for lower health care costs a central part of Mr. Biden’s message to Americans.

And next September, just weeks before Election Day, the administration will announce the results of the yearlong negotiations over the first 10 drugs.

“We plan to work extensively, to really remind folks of this issue,” Ms. Tanden said.

For the people leading Mr. Biden’s re-election campaign, the political benefits of focusing on lower health care costs are clear.

Some polls show that 80 percent of Americans support giving the government the ability to negotiate lower prices for Medicare, much the way it already does for veterans and members of the military.

Campaign aides said talking about lower costs of drugs or limits on out-of-pocket medical expenses is one way to help Mr. Biden win support among seniors, who traditionally have voted for Republicans in greater numbers. That is especially important in battleground states like Michigan, Arizona, Georgia and Ohio, where increasing support among older adults will be critical in close contests.

The campaign’s early television ads have included numerous references to the president’s efforts to lower health care costs. A spokesman for the campaign said the issue of health care would be a central feature of a $25 million ad blitz focusing on what the president has done to lower costs overall and make economic progress.

Kate Bedingfield, who served as Mr. Biden’s communications director for the first two years of his presidency, said the issue had political benefits even when it came to appealing to people who do not benefit directly from the specific cost reductions.

“It draws a really clear contrast with the Republicans, who have stood in the way and continue to stand in the way of getting more done on this,” she said.

Representative Michael C. Burgess, Republican of Texas and a doctor, said Mr. Biden’s drug price negotiations were akin to government-imposed price controls that would lead to drug shortages.

“This administration’s approach goes beyond ‘negotiation,’” he said in a statement. “Instead, it holds pharmaceutical companies hostage, jeopardizing their future innovation and the well-being of American patients.”

Mr. Biden’s campaign aides said a debate with Republicans about the cost of medical care was one they were eager to have.

“MAGA Republicans running for president want to repeal the Inflation Reduction Act, which would deliver a massive win for Big Pharma and increase costs for the American people,” said Julie Chávez Rodríguez, the president’s campaign manager, referring to Republicans loyal to former President Donald J. Trump.

She said the choice in the election was between Mr. Biden and “a slate of candidates focused on extreme policies that put their wealthy donors first.”

Robert Jimison contributed reporting.