The courts have generally held that direct taxes are limited 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).) Various other taxes are commonly referred to as "indirect taxes," because they tax an event, rather than somebody or property by itself. (Steward Machine Co. v. Davis, 301 U.S. 548, 581-582 (1937).) What got a straightforward limitation on the power of the legislature ...