Three states have joined a lawsuit challenging the constitutionality of the Dodd-Frank Act, complaining it gives the government too much power to take over and liquidate nonbank companies when their failure would jeopardize the financial system.

Michigan, Oklahoma and South Carolina joined a broader suit attacking Dodd-Frank that was filed in June in U.S. District Court for the District of Columbia by a Texas community bank, the Competitive Enterprise Institute and the 60 Plus Association.