Questions over the range and applicability of the Commerce Clause have arisen in debate over the constitutionality of the Patient Protection and Affordable Care Act ("PPACA"). The debate centers on whether Congress is authorized to require citizens to purchase health insurance from the private market, known as the "individual mandate". Although Congress claims authority from the Commerce Clause many opponents of the PPACA claim that the individual mandate exceeds Congress's authority, primarily on the position that the law attempts to define the nonpurchase of insurance as "commerce."