s to deprive the federal courts of jurisdiction over a
controversy between him and a citizen of a State.[1062] But power to
naturalize aliens may be, and early was, devolved by Congress upon state
courts having a common law jurisdiction.[1063] Also States may confer
the right of suffrage upon resident aliens who have declared their
intention to become citizens, and have frequently done so.[1064]

RIGHT OF EXPATRIATION: LOSS OF CITIZENSHIP

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] B