After multiple failed attempts by Republican lawmakers to dismantle Obamacare, Donald Trump moved Thursday to unilaterally unravel the nation’s 2010 health-care law. Hours after he signed an executive order rolling back key health insurance regulations protecting consumers, the president announced that he will eliminate critical subsidies to insurance companies that help low-income Americans afford coverage. The two-pronged strike is predicted to cause health-insurance premiums to skyrocket, potentially making doctor’s visits unaffordable for 1 million people, and raises questions about the future of a $3 trillion health-care industry now thrown into chaos.

There doesn’t appear to be any policy upside to Trump’s move to sabotage the current health-care system, except to use its failure as leverage to pass a new law. The Congressional Budget Office, the government’s nonpartisan scorekeeper, predicts that scrapping cost-sharing reduction (C.S.R.) payments would raise premiums by 20 percent in 2018 and 25 percent in 2020. Without those cost-sharing subsidies, expected to total about $100 billion over the next decade, many insurers may withdraw from underserved health-care markets, potentially leaving rural areas without any coverage options. “It is a spiteful act of vast, pointless sabotage leveled at working families and the middle class,” Democratic leaders Senator Chuck Schumer and Congresswoman Nancy Pelosi said in a joint statement. Trump, they added, had “apparently decided to punish the American people for his inability to improve our health-care system.”

The White House argued in a statement Thursday that “The government cannot lawfully make the cost-sharing reduction payments,” referring to a 2014 lawsuit filed by House Republicans that argued the Obama administration was supporting insurance companies illegally. But Trump himself did not appear to shy away from the implication that he had undermined the A.C.A. in order to force Democrats to the negotiating table. “The Democrats ObamaCare is imploding. Massive subsidy payments to their pet insurance companies has stopped,” he wrote on Twitter Friday morning. “Dems should call me to fix!”

The cost-sharing payments, which are disbursed in monthly installments, will stop almost immediately. While some companies had already raised their prices in anticipation of such a move, many more will now pass the costs to consumers. The president’s other executive action scrapping A.C.A. regulations, meanwhile, might lower prices for some, but only by spiking premiums for others. In a directive to federal agencies, the president laid the groundwork to allow companies to sell less expensive, bare-bones insurance plans that don’t meet Obamacare guidelines. Critics of the order argue that the move could price sick people out of the health-care market, as healthier, younger individuals flee to less comprehensive plans. “The clear intent of the executive order is to create a parallel insurance market exempt from many of the consumer protections in the Affordable Care Act,” Larry Levitt, a senior vice president at the Kaiser Family Foundation, told Vox. “This has the potential to siphon off healthy people with skinnier benefits and cheaper premiums, leaving behind a sicker pool of people under A.C.A. plans.” The overall effect could be to create the feared “death spiral” in insurance markets, causing the current system to collapse.

Some Republicans protested the moves. “Cutting health care subsidies will mean more uninsured in my district. @POTUS promised more access, affordable coverage,” Florida Congresswoman Ileana Ros-Lehtinen, who is retiring after this term, wrote on Twitter. “This does opposite.” Still, a bipartisan deal to codify C.S.R. payments and shore up the Obamacare markets seems unlikely. While Republican Senator Lamar Alexander and Democratic Senator Patty Murray have been working on a deal to strengthen Obamacare in exchange for increased flexibility for states, the White House said on Friday that it won’t support a “clean” Murray-Alexander bill without getting even more in return. “The president has said pretty clearly that he’s willing to talk to just about anybody about repealing and replacing [Obamacare],” budget director Mick Mulvaney told Politico. “But if the straight-up question is: Is the president interested in continuing what he sees as corporate welfare and bailouts for the insurance companies? No.”

This article has been updated.