In a brief filed in a federal court in Texas, the department said a tax law signed past year by President Donald Trump that eliminated penalties for not having health insurance rendered the so-called individual mandate under Obamacare unconstitutional.
A Trump administration decision not to defend key parts of the Affordable Care Act in a lawsuit seeking to dismantle it could cause chaos and deprive Americans of coverage, local politicians, providers and insurers said on Friday.
If that argument prevails in the courts, it would render unconstitutional Obamacare provisions that ban insurance companies from denying coverage to people with pre-existing conditions - arguably the most popular component of the 2010 health care law. In the case of health care, "fortunately we have 16 other [Democratic attorneys general] who are prepared to do it with us".
She cited a report from health care think tank Kaiser Family Foundation that estimates more than 52 million Americans have pre-existing health problems that would "likely leave them uninsurable" if it weren't for the Affordable Care Act's regulations.
An NBC/Wall Street Journal poll released on Thursday - before the Trump administration decision was unveiled - found health care was the top issue for all voters and that it's an issue where Democrats have an overwhelming advantage.
In announcing the lawsuit back in February, Texas Attorney General Ken Paxton said, "The US Supreme Court already admitted that an individual mandate without a tax penalty is unconstitutional".
The news rallied defenders of the law into action and raised questions among legal scholars about the likelihood it would succeed.
But Sessions also said that he agrees with the Department of Justice's opinion at the time of the 2012 case, that if the mandate is unconstitutional, it is separate from the ACA's other provisions, except those guaranteeing issuance of coverage in the individual and group market.
Before the Affordable Care Act became law, insurance companies routinely declined health insurance coverage to people who had ongoing medical conditions or recent illnesses.
The legal challenge led by the state of Texas argues that these consumer protections - as well as the law's multibillion-dollar program for expanding the Medicaid safety net to poor Americans - should be scrapped because Congress previous year repealed the penalty on Americans who don't have health coverage. Without that form of tax, the new Administration document noted, the ACA mandate to buy insurance would be unconstitutional as beyond Congress's power to regulate interstate commercial activity.
Senior House Democrats on health care committees called the administration's refusal to defend the federal health law a "stunning attack on the rule of law".
"There is no doubt that Republicans are responsible for the rising cost of healthcare premiums and the high likelihood that many will no longer be able to afford basic care at all, and they will face serious blowback in the midterms", the House Democrats' campaign operation said in a statement. "Zeroing out the individual mandate penalty should not result in striking important consumer protections, such as guaranteed issue and community rating rules that help those with pre-existing conditions".
The Trump administration's startling decision to abandon one of the Affordable Care Act's most popular provisions - protections for people with preexisting medical conditions - put Republicans on the defensive Friday and handed Democrats a potentially potent political message.
Diabetes, pregnancy and arthritis are all considered a pre-existing condition.
Meanwhile, California and several other states filed a motion to intervene to defend the law.
Eyles said that AHIP plans to file a brief in the case laying out "more detail about the harm that would come to millions of Americans if the request to invalidate the ACA is granted". Chris Murphy, D-Conn., said in a statement.
Just hours before the Justice Department officially withdrew from the case, three of the staff attorneys who had been working on it withdrew.
Justice Department tells court it won't defend...
The Trump administration's move drew comparisons to the Obama administration's decision, in 2011, to stop defending the constitutionality of the Defense of Marriage Act, a law that barred federal recognition of same-sex unions that were lawful at the state level, and which the Supreme Court later struck down.
Ultimately, we'll all have to wait to see where the court sides on the argument, which is little comfort to the 130 million people with pre-existing conditions who could soon find themselves in a world of financial trouble.