President Donald Trump’s decision to end a provision of the Affordable Care Act that was benefiting roughly 6 million Americans helps fulfill a campaign promise, but it also risks harming some of the very people who helped him win the presidency.

Nearly 70 percent of those benefiting from the so-called cost-sharing subsidies live in states Trump won last November, according to an analysis by the Associated Press. The number underscores the political risk for Trump and his party, which could end up owning the blame for increased costs and chaos in the insurance marketplace.

The subsidies are paid to insurers by the federal government to help lower consumers’ deductibles and co-pays. People who benefit will continue receiving the discounts because insurers are obligated by law to provide them. But to make up for the lost federal funding, health insurers will have to raise premiums substantially, potentially putting coverage out of reach for many consumers.

Some insurers may decide to bail out of markets altogether.

“I woke up, really, in horror,” said Alice Thompson, 62, an environmental consultant from the Milwaukee area who purchases insurance on Wisconsin’s federally run health insurance exchange.

Thompson, who spoke with reporters on a call organized by a health care advocacy group, said she expects to pay 30 percent to 50 percent more per year for her monthly premium, potentially more than her mortgage payment. Officials in Wisconsin, a state that went for a Republican presidential candidate for the first time in decades last fall, assumed the federal subsidy would end when they approved premium rate increases averaging 36 percent for the coming year.

An estimated 4 million people were benefiting from the cost-sharing payments in the 30 states Trump carried, according to an analysis of 2017 enrollment data from the U.S. Centers for Medicare and Medicaid Services. Of the 10 states with the highest percentage of consumers benefiting from cost-sharing, all but one — Massachusetts — went for Trump.

Kentucky embraced former President Barack Obama’s Affordable Care Act under its last governor, a Democrat, and posted some of the largest gains in getting its residents insured. Its new governor, a Republican, favors the GOP stance to replace it with something else.

Roughly half of the estimated 71,000 Kentuckians buying health insurance on the federal exchange were benefiting from the cost-sharing subsidies Trump just ended. Despite the gains from Obama’s law, the state went for Trump last fall even as he vowed to repeal it.

Consumers such as Marsha Clark fear what will happen in the years ahead, as insurers raise premiums on everyone to make up for the end of the federal money that helped lower deductibles and co-pays.

“I’m stressed out about the insurance, stressed out about the overall economy, and I’m very stressed out about our president,” said Clark, a 61-year-old real estate broker who lives in a small town about an hour’s drive south of Louisville. She pays $1,108 a month for health insurance purchased on the exchange.

While she earns too much to benefit from the cost-sharing subsidy, she is worried that monthly premiums will rise so high in the future that it will make insurance unaffordable.

Sherry Riggs has a similar fear. The Fort Pierce, Florida, barber benefits from the deductible and co-pay discounts, as do more than 1 million other Floridians, the highest number of cost-sharing beneficiaries of any state.

She had bypass surgery following a heart attack last year and pays just $10 a visit to see her cardiologist and only a few dollars for the medications she takes twice a day.

Her monthly premium is heavily subsidized by the federal government, but she worries about the cost soaring in the future. Florida, another state that swung for Trump, has approved rate increases averaging 45 percent.

“Probably for some people it would be a death sentence,” she said. “I think it’s kind of a tragic decision on the president’s part. It scares me because I don’t think I’ll be able to afford it next year.”

Rates already were rising in the immediate aftermath of Trump’s decision. Insurance regulators in Arkansas, another state that went for Trump, approved premium increases on Friday ranging from 14 percent to nearly 25 percent for plans offered through the insurance marketplace. Had federal cost-sharing been retained, the premiums would have risen by no more than 10 percent.

In Mississippi, another state Trump won, an estimated 80 percent of consumers who buy coverage on the insurance exchange benefit from the deductible and co-pay discounts, the highest percentage of any state. Premiums there will increase by 47 percent next year, after regulators assumed Trump would end the cost-sharing payments.

The National Association of Insurance Commissioners has estimated the loss of the subsidies would result in a 12 percent to 15 percent increase in premiums, while the nonpartisan Congressional Budget Office has put the figure at 20 percent. Experts say the political instability over Trump’s effort to undermine Obama’s health care law could prompt more insurers to leave markets, reducing competition and driving up prices.

Trump’s move concerned some Republicans, worried the party will be blamed for the effects on consumers and insurance markets.

“I think the president is ill-advised to take this course of action, because we, at the end of the day, will own this,” Republican Rep. Charlie Dent of Pennsylvania said Friday on CNN. “We, the Republican Party, will own this.”

Dent is not running for re-election.

In announcing his decision, Trump argued the subsidies were payouts to insurance companies, and the government could not legally continue to make them. The subsidies have been the subject of an ongoing legal battle because the health care law failed to include a congressional appropriation, which is required before federal money can be spent.

The subsidies will cost about $7 billion this year.

Many Republicans praised Trump’s action, saying Obama’s law has led to a spike in insurance costs for those who have to buy policies on the individual market.

Among them is Republican Rep. Andy Biggs of Arizona, a state Trump won. An estimated 78,000 Arizonans were benefiting from the federal subsidies for deductibles and co-pays.

“While his actions do not take the place of real legislative repeal and revitalization of free-market health care, he is doing everything possible to save Americans from crippling health care costs and decreasing quality of care,” Biggs said.