 And in "United States v. New Mexico", 455 U.S. 720 (1982), the Court enunciated a general policy of upholding taxes against private parties doing business with the federal government absent a specific constitutional or legislative mandate.However, in "Kern-Limerick, Inc. v. Scurlock", 347 U.S. 110 (1954), the Supreme Court held that when a contractor was merely the federal government's purchasing agent, the legal incidence of the tax fell on the United States and hence the tax was invalid.Further rulings by the Supreme Court, however, indicated that "Kern-Limerick" has extremely limited implications for Supremacy Clause jurisprudence and the ruling is limited to the facts in that case.