A lawyer for Texas Attorney General Ken Paxton will be in a federal courtroom Tuesday asking three appellate judges to declare the Affordable Care Act unconstitutional, and this time it will be with the full support of the Trump administration.

The U.S. Department of Justice earlier this year announced that the agency, like Paxton, believes the entire law should be struck down, reversing its previous position that certain sections, including a provision allowing states to expand Medicaid, should not be affected by the case.

Opposing them in Tuesday’s oral arguments at the 5th U.S. Circuit Court of Appeals will be lawyers for the U.S. House and 20 Democratic-led states who say striking down the law would wreak havoc on the health care system and put lives at risk.

The showdown will produce a decision that could give the U.S. Supreme Court another crack at deciding whether the 2010 law, a signature achievement of Democratic President Barack Obama, remains in effect.

At stake is health insurance for about 20 million Americans, either directly through the program sometimes called Obamacare or through expanded Medicaid coverage, as well as protection for millions more who have preexisting medical conditions.