The courts have generally held that direct taxes are restricted to taxes on people (variously called capitation, poll tax or head tax) and property. (Penn Mutual Indemnity Company. v. C.I.R., 227 F.2d 16, 19-20 (3rd Cir. 1960).) All other taxes are typically called "indirect taxes," within their tax an event, rather than somebody or property per se. (Steward Machine Co. v. Davis, 301 U.S. 548, 581-582 (1937).) What were a straightforward limitation on the power of the legislature based on the ma...