States are already lining up to sue the federal government over the constitutionality of President Barack Obama's health care overhaul.
Officials in at least 10 states have agreed to file a lawsuit challenging the legislation.
Texas Attorney General Greg Abbott said he planned to file the complaint "the moment Obama signs the bill."
Abbott pledged to pursue the case "to protect all Texans' constitutional rights, preserve the constitutional framework intended by our nation's founders and defend our state from further infringement by the federal government."
Other states planning to challenge the bill were Alabama, Florida, South Carolina, Nebraska, North and South Dakota, Pennsylvania, Utah and Washington.
Nebraska Attorney General Jon Bruning said the measure "tramples on individual liberty and dumps on the states the burden of an unfunded mandate that taxpayers cannot afford."
Bruning, a Republican, is president of the National Association of Attorneys General. His statement did not explain why he believes the bill is unconstitutional. But other attorneys general have said it violates state sovereignty by mandating that all Americans have some form of health insurance.
The House voted 219-212 late Sunday to approve the overhaul, which would extend coverage to 32 million uninsured Americans and make a host of other changes. Obama could sign the bill as early as Tuesday.