Michigan Attorney General Dana Nessel is seeking to intervene in a federal lawsuit to protect the Affordable Care Act with the support of Gov. Gretchen Whitmer, the officials announced in press releases Thursday night.

Nessel and three other attorneys general are seeking to intervene in a case in which a Texas judge ruled the Affordable Care Act unconstitutional based on a tax change that eliminated the penalty for not carrying insurance. Led by Texas Attorney General Ken Paxton, a group of 20 states brought the suit, arguing that without the penalty the law becomes unenforceable.

Nessel and attorneys general from Colorado, Nevada and Iowa would join 16 other states and the District of Columbia in defending the Affordable Care Act, which Trump instructed the U.S. Department of Justice not to do. In the motion to intervene, the four attorneys general seeking to join the case argue their health care systems would be thrown into disarray if the law were repealed.

“The Affordable Care Act provides important protections – including protecting people with pre-existing conditions – and access to health care for hundreds of thousands of residents in Michigan,” said Nessel in a press release.

“We have a strong interest in ensuring that the strongest possible arguments are presented in support of the ACA.”

Gov. Gretchen Whitmer supports the move.

“Health care for hundreds of thousands of Michiganders is on the line,” Whitmer said in a press release.

“If this decision is upheld, it will make it harder for families across the state to get the care they need. That’s why Attorney General Nessel and I are stepping up to defend the ACA on behalf of the State of Michigan. As governor, I will never stop fighting to ensure everyone in Michigan has access to quality, affordable health care.”

Nessel’s move runs counter to how previous Michigan attorneys general have treated the Affordable Care Act, sometimes referred to colloquially as “Obamacare.” Former Attorney General Bill Schuette and former Attorney General Mike Cox argued against the Affordable Care Act in other court cases, though Michigan was not previously involved in this particular case.

Nessel has also recently reversed course on several national lawsuits Schuette had joined, including some on abortion; separation of church and state; and environmental regulations.

The Associated Press contributed to this report.