“ The power to regulate commerce with foreign nations is expressly conferred upon Congress, and, being an enumerated power, is complete in itself, acknowledging no limitations other than those prescribed in the Constitution. ”

“ As a result of the complete power of Congress over foreign commerce, it necessarily follows that no individual has a vested right to trade with foreign nations which is broad in character as to limit and restrict the power of Congress to determine what articles of merchandise may be imported into this country and the terms upon which a right to import may be exercised. This being true, it results that a statute which restrains the introduction of particular goods into the United States from considerations of public policy does not violate the due process clause of the Constitution. ”

“ Whatever difference of opinion, if any, may have existed or does exist concerning the limitations of the power, resulting from other provisions of the Constitution, so far as interstate commerce is concerned, it is not to be doubted that from the beginning Congress has exercised a plenary power in respect to the exclusion of merchandise brought from foreign countries ”