(CNN) -- The Trump administration won't defend central provisions of the Affordable Care Act, saying in a legal filing Thursday night that key parts of the Affordable Care Act should be invalidated and that the individual mandate is unconstitutional. The filing came in a lawsuit brought by the state of Texas and a coalition of other Republican-led states who have filed suit in the United States District Court for the Northern District of Texas challenging the constitutionally of the Affordable Care Act. The states argue that after Congress eliminated the penalty for the individual mandate last year, effective in 2019, it destabilized other sections of the law. "In its filing the DOJ said that it agrees with Texas that the individual mandate is now unconstitutional and therefore it will not defend key provisions of the law in the suit," said Timothy Jost, of Washington and Lee University School of Law. The provisions DOJ says should be invalidated are central to the ACA and would gut protections for those with pre-existing conditions.