Notwithstanding evidence in early court decisions[1065] and in the Commentaries of Chancellor Kent of a brief acceptance of the ancient English doctrine of perpetual and unchangeable allegiance to the government of one's birth, whereby a citizen is precluded from renouncing his allegiance without permission of that government, the United States, since enactment of the act of 1868,[1066] if indeed not earlier, has expressly recognized the right of everyone to expatriate himself and choose another country. Retention of citizenship is not dependent entirely, however, upon the desires of the individual; for, although it has been "conceded that a change of citizenship cannot be arbitrarily imposed, that is, imposed without the concurrence of the citizen," the United States, by virtue of the powers which inhere in it as a sovereign nation, has been deemed competent to provide that an individual voluntarily entering into certain designated conditions shall, as a consequence thereof, suffer the loss of citizenship.[1067] Exclusion of Aliens The power of Congress "to exclude aliens from the United States and to prescribe the terms and conditions on which they come in" is absolute, being an attribute of the United States as a sovereign nation. In the words of the Court: "That the government of the United States, through the action of the legislative department, can exclude aliens from its territory is a proposition which we do not think open to controversy. Jurisdiction over its own territory to that extent is an incident of every independent nation. It is a part of its independence. If it could not exclude aliens, it would be to that extent subject to the control of another power. * * * The United States, in their relation to foreign countries and their subjects or citizens are one nation, invested with powers which belong to independent nations, the exercise of which can be invoked for the maintenance of its absolute independence and security throughout its entire territory."[1068] By the Immigration and Nationality Act of June 27, 1952, some thirty-one categories of aliens are excluded from the United States[1069] including "aliens who are, or at any time have been, members * * * of or affiliated with any organization that advocates or teaches * * * the overthrow by force, violence, or other unconstitutional means of the Government of the United States * * *"[1070]