The Democrats' brief said the ACA has been "instrumental in our Nation's response to the COVID-19 pandemic," citing support by the ACA's Prevention and Public Health Fund for efforts to track the spread of coronavirus, enhance laboratory capacity, and expand diagnostic testing.

As Democratic-led states filed a brief with the U.S. Supreme Court opposing repeal the Affordable Care Act, Speaker of the House Nancy Pelosi says the current COVID-19 pandemic is demonstrating the ACA's  relevance.

"The Affordable Care Act is a pillar of health and economic security in America, and its protections are more important than ever, as the coronavirus crisis shatters the lives and livelihoods of millions," Pelosi said.  "As our brief makes clear, the President's insistence on doubling down on his senseless and cruel argument in court to destroy the ACA and every last one of its benefits and protections is unconscionable, particularly in the middle of a pandemic."

Related: What does the COVID-19 pandemic mean for the ACA lawsuit?

California Attorney General Xavier Becerra said critical public health programs that help fight COVID-19 are among the provisions of the law that could be struck down.

"It's unconscionable that the Trump Administration continues its attack on health care, just when many Americans across the country need it most. A global pandemic is the time to wake up and protect the lives of our loved ones, yet all we see from the President's team is repeal without replace," said Becerra.

Becerra leads a coalition of 20 Democrat-led states that filed a petition opposing repeal of the ACA on May 6. The Democrats' brief said the ACA has been "instrumental in our Nation's response to the COVID-19 pandemic," citing support by the ACA's Prevention and Public Health Fund for efforts to track the spread of coronavirus, enhance laboratory capacity, and expand diagnostic testing. The Democrats' brief also cites the ACA's "essential health benefits" provision, which requires insurers to cover  the costs of diagnosis and treatment, and will require them to cover the cost of an approved vaccine; and its provision allowing Americans who lose their jobs and health insurance to purchase coverage through the ACA's Exchanges and to obtain subsidies for that coverage.

At issue in the case before the court is a recent Fifth Circuit decision that held the ACA's individual mandate unconstitutional and called into question whether the remaining provisions of the law could still stand. The ruling came in a suit by 20 Republican state attorneys general and Republican governors, led by Texas, challenging the constitutionality of the ACA's individual mandate in light of legislation enacted by Congress in 2017 that eliminated the individual mandate penalty. President Trump said on May 6 that his administration would support the Republican-led effort.

Related: 

• As coronavirus rages, Biden hits Trump over ACA challenge
• How uncertainty over ACA is affecting health care
• AHIP president: Supreme Court will save most of ACA