Potter Stewart

“ Different considerations do not govern merely because this is a naturalization case. When the Government seeks to strip a person of citizenship already acquired, [9] or deport a resident alien and send him from our shores, [10] it carries the heavy burden of proving its case by 'clear, unequivocal, and convincing evidence.' [11] But when an alien seeks to obtain the privileges and benefits of citizenship, the shoe is on the other foot. He is the moving party, affirmatively asking the Government to endow him with all the advantages of citizenship. ”

“ Even assuming that an alien may be denied citizenship on the statutory ground of Party membership only when 'meaningful association' is shown, the broader question asked of the petitioner was certainly material and relevant. The Government is entitled to know of any facts that may bear on an applicant's statutory eligibility for citizenship, so that it may pursue leads and make further investigation if doubts are raised. ”

“ Because that status, once granted, cannot lightly be taken away, the Government has a strong and legitimate interest in ensuring that only qualified persons are granted citizenship. For these reasons, it has been universally accepted that the burden is on the alien applicant to show his eligibility for citizenship in every respect. ”