Felix Frankfurter,
Perez v. Brownell — Opinion of the Court
“ It cannot be said, then, that Congress acted without warrant when, pursuant to its power to regulate the relations of the United States with foreign countries, it provided that anyone who votes in a foreign election of significance politically in the life of another country shall lose his American citizenship. To deny the power of Congress to enact the legislation challenged here would be to disregard the constitutional allocation of governmental functions that it is this Court's solemn duty to guard. ”
