In proceedings to deport a person born in the United States, the Government denied that he was an American citizen on the ground that, by voting in a Mexican political election and remaining outside of the United States in wartime to avoid military service, he had lost his citizenship under 401 (e) and (j) of the Nationality Act of 1940, as amended. He sued for a judgment declaring him to be a citizen but was denied relief. Held: It was within the authority of Congress, under its power to regulate the relations of the United States with foreign countries, to provide in 401 (e) that anyone who votes in a foreign political election shall lose his American citizenship; and the judgment is affirmed. Pp. 45-62.

(a) The power of Congress to regulate foreign relations may reasonably be deemed to include a power to deal with voting by American citizens in foreign political elections, since Congress could find that such activities, because they might give rise to serious international embarrassment, relate to the conduct of foreign relations. Pp. 57-60.

(b) Since withdr