In Standard Dredging Corp. v. Murphy, 319 U.S. 306, 310, 63 S. Ct. 1067, 1069, 87 L. Ed. 1416, 1420 (1943) New York collected unemployment insurance taxes from employers of maritime workers. The employers challenged the tax, arguing that since FUTA exempted employers of maritime workers from federal unemployment taxes, Congress had declared expressly or by implication that no such tax should be imposed by the state. Id. at 307, 63 S. Ct. at 1068, 87 L. Ed. at 1418-19. The Supreme Court rejected the employers' preemption claim, reasoning that the federal exemption had been created because of certain administrative difficulties regarding coverage. The Court found no evidence that Congress intended to prevent states from tackling those difficulties, if they so chose. The Court stated: The federal Act, from the nature of its ninety per cent credit device, is obviously an invitation to the states to enter the field of unemployment insurance . . . but the absence of an invitation as to employers of maritime workers is not to be construed as a barrier to state action.Id. at 310, 63 S. Ct. at 1069, 87 L. Ed. at 1420. The Court added: The legislative history of other exemptions may indicate that they were intended to oust the states of jurisdiction . . .; but current administrative practice under the Act indicates that there is nothing in the mere existence of a federal exemption which necessarily required that states not undertake to expand the social security program in this field. Id. at 311, 63 S. Ct. at 1069, 87 L. Ed. at 1421.