A declaration of candidacy requires both filing the appropriate candidacy form (Form 2 with FEC for federal elections or equivalent state/local form) AND a clear, unambiguous public statement explicitly declaring intention to seek the office. The declaration must be made directly by the person or their officially authorized representatives, explicitly reference the specific office, be publicly accessible through Source Agencies, and occur after market issuance. Formation of exploratory committees, third-party statements, media speculation, "considering" statements, private communications, or fundraising without explicit declaration do not qualify. The person must be legally eligible to hold the office under applicable constitutional and statutory requirements.