Felix Frankfurter,
Baumgartner v. United States — Opinion of the Court
“ Nothing that we are now deciding is intended to weaken in the slightest the alertness with which admission to American citizenship should be safeguarded. But we must be equally watchful that citizenship once bestowed should not be in jeopardy nor in fear of exercising its American freedom through a too easy finding that citizenship was disloyally acquired. We have sufficiently indicated the considerations of policy, derived from the traditions of our people, that require solid proof that citizenship was falsely and fraudulently procured. ”
