After a quiet century or so, the scope of Congress’s power “[t]o lay and collect taxes” is once again in the news. The taxing power was at issue when the Supreme Court issued a decision that President (and Chief Justice) Taft would later call the worst injury to the Court’s reputation ever, Pollock v. Farmers’ Loan & Trust, striking down the Income Tax Act of 1894. That decision was largely reversed by the 1913 enactment of the Sixteenth Amendment. Today the taxing power is one of three grounds on which the federal government defends the constitutionality of the Patient Protection and Affordable Care Act, particularly the individual responsibility requirement (IRR)—the portion of the Act requiring each individual to purchase insurance or pay a penalty tax.
Brian D. Galle. "The Taxing Power, the Affordable Care Act, and the Limits of Constitutional Compromise." Yale Law Journal Online 121, (2011): 407-420.