Constitutionally, Puerto Rico is subject to the plenary powers of the United States Congress under the territorial clause of Article IV of the U.S. Constitution. Laws enacted at the federal level in the United States apply to Puerto Rico as well, regardless of its political status. Their residents do not have voting representation in the U.S. Congress. Like the different states of the United States, Puerto Rico lacks "the full sovereignty of an independent nation", for example, the power to manage its "external relations with other nations", which is held by the U.S. federal government. The Supreme Court of the United States has indicated that once the U.S. Constitution has been extended to an area (by Congress or the courts), its coverage is irrevocable. To hold that the political branches may switch the Constitution on or off at will would lead to a regime in which they, not this Court, say "what the law is".