In a letter, it said the appeals court should affirm a December decision by a federal judge in Texas.
The Justice Department has determined that O'Connor's "comprehensive opinion came to the correct conclusion and will support it on appeal", said departmental spokeswoman Kerri Kupec.
Although President Trump has railed against Obamacare for years and has frequently called for its repeal and replacement, he and other Republicans have insisted that they support protecting coverage for pre-existing conditions. Lawyers under Sessions had argued that only parts of the Obama-era health care law were unconstitutional after Congress effectively repealed its tax penalty in 2017 for people without insurance.
Axios health care reporter Sam Baker writes that the lawsuit will have a "cataclysmic" impact on Americans' health care if it succeeds in gutting the entire health care law, including popular provisions such as the expansion of Medicaid, the banning of discrimination against people with preexisting conditions, and letting young people stay on their parents' health insurance until the age of 26. He has continually scapegoated John McCain for his part in rejecting an attempt to overhaul health care, even doing so after the revered senator died past year.
If it were successful, the Justice Department's position supporting the judge's ruling would potentially eliminate health care for millions of people and create widespread disruption across the USA health care system - from removing no-charge preventive services for older Americans on Medicare to voiding the expansion of Medicaid in most states. In a pre-election CBS News poll, 68 percent of respondents said that health care would be a very important issue in deciding their votes. Democrats have been casting about for a message after Special Counsel Robert Mueller found no conspiracy between candidate Donald Trump and the Russian government to sway the 2016 election.
In 'major shift, ' Department of Justice argues...
The administration's move didn't only startle supporters of the law.
"Last night, the Department of Justice declared the entire law and all of its vital health care protections must go", Senate Minority Leader Chuck Schumer, a Democrat from NY, said in remarks on the Senate Floor on Tuesday.
Sen. Kamala Harris, one of the Democrats running for president in 2020, addressed the issue on "CBS This Morning" Tuesday. People close to her say she has serious reservations about the single-payer bill and believes the nation can achieve the goal of universal coverage at a more manageable cost by building on the framework of the Affordable Care Act, which she worked tirelessly to secure in 2010. People are anxious, especially my part of the country about children being born with diabetes and how they are going to get health care.
"Democrats are doing what the American people elected us to do - stand up for them". However, during the 2017 congressional debate over repealing the health law, the nonpartisan Congressional Budget Office estimated the GOP replacement plans would result in steep coverage losses.
"At the end of the day, I don't think this is going to have a big effect", Adler said.