Less than one year after passage, the Patient Protection and Affordable Care Act (“PPACA”; “Act”)1 — part of the Obama Administration’s healthcare reform legislation signed into law on March 23, 2010 — already is the subject of numerous legal challenges. The following is a summary of the pending cases.

As of this writing,3 twenty-one lawsuits4 have been filed challenging the constitutionality of the PPACA. With some variation, the lawsuits generally challenge the Act on one or more of the following bases: (i) the Act is an unlawful expansion of Congress’s power to regulate interstate commerce in violation of the Commerce Clause, Art. I, § 8; (ii) the individual health insurance mandate is an unapportioned direct tax on the people, in violation of the Direct Tax prohibition, Art. I, § 9; (iii) certain aspects of the passage of the legislation violated the Constitution’s guarantee of a republican form of government, Art. IV, § 4; (iv) the Act infringes upon individuals’ religious beliefs in violation of the First Amendment; (v) the Act’s individual insurance mandate constitutes an unreasonable seizure in violation of the Fourth Amendment; (vi) the Act takes private property for public use and deprives individuals of property without due process of law, in violation of the Fifth Amendment Takings Clause and the Due Process Clause; (vii) the Act infringes upon the unenumerated rights retained in the people in violation of the Ninth Amendment; (viii) the Act commandeers state government, mandates compensation that states must pay to elected officials, and forces the states to impose a tax increase in violation of the Tenth Amendment; and (ix) the Act violates the Fourteenth Amendment guarantees of due process and equal protection.