Final answer:
The U.S. Supreme Court upheld the constitutionality of the Patient Protection and Affordable Care Act under the taxing clause in a 5-4 decision in 2012. The ACA includes various taxes to fund its provisions, and the Court has since served as the critical judicial body overseeing subsequent challenges to the law.
Step-by-step explanation:
In 2012, the Supreme Court ruled on the constitutionality of the Patient Protection and Affordable Care Act (ACA), often referred to as Obamacare. This landmark decision, National Federation of Independent Business v. Sebelius, addressed whether Congress had the power to enact components of the ACA.
Critics opposed to the ACA's individual mandate, which required individuals to purchase health insurance or face a penalty, challenged this aspect as unconstitutional. The Supreme Court, in a split 5-4 decision, upheld the individual mandate, interpreting it as a form of taxation which falls under Congress's enumerated power to tax, thus confirming its constitutionality.
The ACA is funded through various additional taxes, such as the increase of the Medicare tax and a tax on unearned income for higher income taxpayers, an annual fee on health insurers, and a tax on certain medical device manufacturers and importers.