The Trump administration has asked the Supreme Court to invalidate Affordable Care Act, known as Obamacare, which has provided health insurance to millions of Americans.
According to government lawyers, Obamacare became invalid when the previous Republican-led Congress axed parts of it.
Democratic challenger Joe Biden attacked the move, saying President Donald Trump had put millions of lives at risk during the coronavirus pandemic.
Health care will be a key battleground in this year’s presidential election.
Some 20 million Americans could lose their health coverage if the court overturns the Affordable Care Act (ACA), which was introduced by President Barack Obama.
Obamacare’s popular provisions include banning insurers from denying coverage due to pre-existing conditions and allowing children to stay on their parents’ health plans until age 26. Millions of low-income Americans were able to obtain insurance due to the act.
President Trump says the scheme costs too much and has promised a different plan to replace it, preserving some popular elements of the existing law but covering fewer people.
Under Obamacare, millions of people in the US must purchase health insurance or face a tax penalty.
In 2017, Congress removed a key plank of the policy, eliminating the federal fine for those who did not sign up, known as the “individual mandate”.
In its filing to the Supreme Court on June 25, the justice department argued “the individual mandate is not severable from the rest of the act”.
As a result, it said: “The mandate is now unconstitutional as a result of Congress’s elimination… of the penalty for non-compliance.”
President Trump cannot rely on Congress to complete the dismantling of Obamacare because the Democrats took control of the lower house in 2019.
Joe Biden, who wants to rally the public behind an expanded Affordable Care Act, said some coronavirus survivors could lose their comprehensive healthcare coverage if the act was overturned.
He said: “They would live their lives caught in a vice between Donald Trump’s twin legacies: his failure to protect the American people from the coronavirus, and his heartless crusade to take healthcare protections away from American families.”
In a statement on June 26, White House spokesman Judd Deere said Obamacare was “an unlawful failure”.
The statement said: “It limits choice, forces Americans to purchase unaffordable plans, and restricts patients with high-risk preexisting conditions from accessing the doctors and hospitals they need.”
The US has been badly hit by the coronavirus pandemic, recording 2.4 million confirmed Covid-19 cases and 122,370 deaths – more than any other country.
However, the true number of infections is likely to be 10 times higher than the reported figure, according to the latest estimate by health officials.
The Supreme Court is unlikely to hear the case before voters go to the polls in November, media report.