by John Marshall Harlan

“ The power to exclude aliens and the power to expel them rest upon one foundation, are derived from one source, are supported by the same reasons, and are in truth but parts of one and the same power. The power of congress, therefore, to expel, like the power to exclude, aliens, or any specified class of aliens, from the country, may be exercised entirely through executive officers; or congress may call in the aid of the judiciary to ascertain any contested facts on which an alien's right to be in the country has been made by congress to depend. ”

“ This court, observing that, according to the accepted maxims of international law, every sovereign nation has the power, inherent in sovereignty and essential to self preservation, to forbid the entrance of foreigners within its dominions, or to admit them only in such cases and upon such conditions as it may see fit to prescribe, said: 'In the United States this power is vested in the national government, to which the constitution has committed the entire control of international relations, in peace as well as in war. ”

“ The contention is that while, generally speaking, immigration officers have jurisdiction under the statute to exclude an alien who is not entitled under some statute or treaty to come into the United States, yet if the alien is entitled of right, by some law or treaty, to enter this country, but is nevertheless excluded by such officers, the latter exceed their jurisdiction, and their illegal action, if it result in restraining the alien of his liberty, presents a judicial question, for the decision of which the courts may intervene upon a writ of habeas corpus. ”