The peculiar nature of the US Federal Constitution impinges on the implementation of any federal legislation. The tenth amendment to the US Constitution lays down that powers "not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the States respectively...." What this amendment means is that political authority is vested in the states unless preempted by the federal government. The most obvious example of federal pre-emption is that of equal rights legislation for African Americans. Such federal action has traditionally come about as a result of the perceived failure of states in the civil rights area. Historically environmental issues were the responsibility of the states. However the emergence of the Green movement in the '70s (like the Civil Rights movement of the '60s) has led to greater involvement by the federal government.
Nevertheless the role of the states remains central to environmental policy implementation and in some cases their legislation has been even stricter than federal laws. (Helme & Pearce 1991).
Moreover the constitutional rights of states can be sued to the detriment of federal policy. This allows the states some room for manoeuvre in their dealings with the federal government on environmental issues. This is especially so as full federal pre-emption, as we shall see, can carry with it unacceptable costs and inadequate levels of control.
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