Twenty-one states and several other entities have filed lawsuits challenging the constitutionality of some sections of the recently enacted federal health care overhaul.

Florida is leading 19 other states, for example, in a federal lawsuit that claims that a "mandate" that individuals buy coverage, which goes into effect in 2014, is unconstitutional. People who choose to forgo insurance will face tax penalties under the new law. (However, insurance subsidies will be provided on a sliding scale to people with incomes between 133 percent and 400 percent of the federal poverty level, which for 2010 is from $29,326 to $88,200 for a family of four.)

The lawsuit filed on March 23 in U.S. District Court for the Northern District of Florida claims that the overhaul of the U.S. health care system also violates state-government rights and will force massive new spending on state budgets already strained by the recession. A federal judge, Roger Vinson, has set an expedited schedule for the case, with opening arguments beginning on September 14.

The state attorneys general who brought the suit also maintain that numerous special provisions for various states included in the law violate the Constitution's requirement that Congress make laws for the general welfare. Legislative deals, such as an exemption from cuts for Medicare Advantage enrollees in Florida—referred to by critics as GatorAid, may violate requirements that federal law apply equally across states.

Most of the lawsuits are led by Republican state officials, who view the law as unconstitutional because for the first time a federal law requires people to buy insurance from a private company whether or not they want it. Such a requirement, critics say, violates the 10th Amendment, which states that powers not granted to the national government are reserved for states or the people.

Supporters counter that the Constitution's commerce and spending clauses give Congress the authority to make such requirements, and they cite key Supreme Court decisions over the last 70 years to support this claim. Additionally, opponents of these lawsuits argue that states don't have standing to sue because the insurance mandate doesn't require anything of state governments. Rather, the mandate to buy insurance is levied on individuals.

To address that potential stumbling block, Kevin Calvey, a Republican Oklahoma congressional candidate, filed a federal lawsuit on behalf of himself and 15 others claiming that Congress lacks the authority to require private citizens to purchase health insurance.

Separately, Virginia has filed a lawsuit that argues that the federal law's requirements that most Americans buy health insurance clashes with a state law exempting Virginians from federal fines for not owning health insurance policies.

Political leaders in several other states where the legislature or leaders of the executive branches are from differing parties also are considering finding ways of joining the larger combined state suit. Leaders of Oklahoma's Republican-controlled legislature were looking to hire private attorneys to join the 20-state lawsuit. The state's Democratic governor and attorney general declined to join the lawsuit. In Georgia, the Democratic attorney general is facing an impeachment resolution after he refused the Republican governor's request to sue the government.

Additionally, Florida residents will vote in November on a proposed constitutional amendment that would bar the government from forcing people in that state to buy health insurance.