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 Organization. v. C.I.R., 227 F.2d 16, 19-20 (3rd Cir. 1960).) Any other taxes are known as "indirect taxes," because they tax an event, rather than person or property per se. (Steward Machine Co. v. Davis, 301 U.S. 548, 581-582 (1937).) What turned out to be a straightforward limitation on the power of the legislature base...