topic: power to tax and spend
Pollock v. Farmers' Loan and Trust Company 157 U.S. 429 (1895)
Pollock v. Farmers' Loan & Trust Company (Rehearing) 158 U.S. 601 (1895)
McCray v. United States 195 U.S. 27 (1904)
Bailey v. Drexel Furniture Company 259 U.S. 20 (1922)
United States v. Butler 297 U.S. 1 (1936)
Steward Machine Co. v. Collector of Internal Revenue 301 U.S. 548 (1937)
Helvering v. Davis 301 U.S. 619 (1937)
Mulford v. Smith 307 U.S. 38 (1939)