Georgia Attorney General Chris Carr has joined a challenge to the federal law commonly known as Obamacare pending in the U.S. District Court for the Northern District of Texas.

“The Affordable Care Act's design was constitutionally flawed at the outset,” Carr said in a news release Tuesday. “Our office has pushed back against this overt form of federal overreach from the beginning, and we will continue to work with other states to see that it is resolved in a way that protects the interests of our citizens.”

Carr has united with a 20-state coalition urging a federal judge in Fort Worth to declare the ACA's individual mandate unconstitutional and to enjoin enforcement of the entire law. The complaint, filed late Monday, argued that the ACA, as recently amended, “forces an unconstitutional and irrational regime onto the states and their citizens.”

In a 2012 decision in NFIB v. Sebelius, the U.S. Supreme Court upheld the core provision of the act—the mandate that each individual must carry health coverage, or else pay a penalty—as a tax. However, Congress recently repealed the tax penalty tied to that mandate, while leaving the mandate in place. The attorneys general argue that, since the Supreme Court has already held that Congress has no authority to impose such a mandate without invoking its taxing power, the ACA in its amended form is unconstitutional.

Texas Attorney General Ken Paxton and Wisconsin Attorney General Brad Schimel are leading the challenge. In addition to Georgia and Wisconsin, the following states also joined the coalition: Alabama, Arizona, Arkansas, Florida, Indiana, Kansas, Louisiana, Maine, Mississippi, Missouri, Nebraska, North Dakota, South Carolina, South Dakota, Tennessee, Utah and West Virginia.

“Texans have known all along that Obamacare is unlawful and a divided Supreme Court's approval rested solely on the flimsy support of Congress' authority to tax. Congress has now kicked that flimsy support from beneath the law,” Paxton said in a news release. “The U.S. Supreme Court already admitted that an individual mandate without a tax penalty is unconstitutional. With no remaining legitimate basis for the law, it is time that Americans are finally free from the stranglehold of Obamacare, once and for all.”