宪法上说的清清楚楚(Clause 5 of Section 1 of Article II)没有任何歧义

Qualifications for office
No person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty-five Years, and been fourteen Years a Resident within the United States.

By the time of their inauguration, the President and Vice President must be:

natural born citizens, or citizens, at the time of the Constitution's adoption
at least thirty-five years old
inhabitants for at least fourteen consecutive years of the United States.