A short history of Congress's power to tax

The first enumerated power that the Constitution grants to Congress is the “power to lay and collect taxes, duties, imposts, and excises, to pay the debts and provide for the common defense and general welfare of the United States.” The text indicates that the taxing power is not plenary, but can be used only for defined ends and objects—since a comma, not a semicolon, separated the clauses on means (taxes) and ends (debts, defense, welfare). …

Other direct taxes should presumably have to be apportioned according to the Constitution. Justice Roberts quickly dismissed the notion that the individual mandate penalty-tax is not a direct tax “under this Court’s precedents.” To any sentient adult, it looks like a “capitation” or head tax, imposed upon individuals directly. Unfortunately, having plenty of other reasons to object to ObamaCare, the four dissenting justices in NFIB v. Sebelius did not explore this point.