The Constitution imposes three eligibility requirements on the presidency—based on the officeholder’s age, residency, and citizenship—that must be satisfied at the time of taking office. By virtue of the Twelfth Amendment, the qualifications for vice president are the same. The Framers established these qualifications in order to increase the chances of electing a person of patriotism, judgment, and civic virtue.

First, presidents must be thirty-five years of age or older. In contrast, senators must be at least thirty years old, and representatives no less than twenty-five years old. As Justice Joseph Story has noted in his Commentaries on the Constitution of the United States (1833), the “character and talents” of a man in the middle age of life are “fully developed,” and he has had the opportunity “for public service and for experience in the public councils.”

Second, the president must have been a “resident” of the United States for fourteen years. By contrast, to be a member of Congress, one must be an “inhabitant” of the state one is representing. During the Constitutional Convention, James Madison contended that “both [terms] were vague, but the latter [‘Inhabitant’] least so in common acceptation, and would not exclude persons absent occasionally for a considerable time on public or private business.” Then as now, inhabitant meant being a legal domiciliary, but resident could mean either a domiciliary or a physical presence. Perhaps the Framers desired a person as president who had actually been present in the United States for the required period and had developed an attachment to and understanding of the country, rather than one who was legally an inhabitant, but who may have lived abroad for most of his life. On the other hand, the distinction may have been one of style rather than substance. As Justice Story later noted, “[b]y ‘residence,’ in the constitution, is to be understood, not an absolute inhabitancy within the United States during the whole period; but such an inhabitancy, as includes a permanent domicil in the United States.”

There is some evidence that the Framers believed the fourteen-year residency requirement could be satisfied cumulatively, rather than consecutively. An earlier version of the clause excluded individuals who have “not been in the whole, at least fourteen years a resident within” the United States, and historical evidence suggests that deletion of the phrase “in the whole” was not intended to alter the provision’s meaning. This might explain the election of Herbert Hoover, whose successful 1928 campaign for president came less than fourteen years after his return to the United States in 1917. Others may argue that Hoover had simply maintained a United States domicile throughout his tenure abroad.

The third qualification to be president is that one must be a “natural born Citizen” (or a citizen at the time of the adoption of the Constitution). Although any citizen may become a member of Congress so long as he has held citizenship for the requisite time period, to be president, one must be “a natural born Citizen.” Undivided loyalty to the United States was a prime concern. During the Constitutional Convention, John Jay wrote to George Washington, urging “a strong check to the admission of Foreigners into the administration of our national Government; and to declare expressly that the Commander in Chief of the American army shall not be given to nor devolve on, any but a natural born Citizen.” Justice Story later noted that the natural born citizenship requirement “cuts off all chances for ambitious foreigners, who might otherwise be intriguing for the office.”

Under the longstanding English common law principle of jus soli, persons born within the territory of the sovereign (other than children of enemy aliens or foreign diplomats) are citizens from birth. Thus, persons born within the United States are plainly “natural born citizens” eligible to be president.

Being born on U.S. soil is not the only way for a person to be entitled to U.S. citizenship at birth, however. A person can be a citizen from birth based on the citizenship of one or both parents—under a British doctrine known as jus sanguinis. The First Congress codified that doctrine into U.S. law, declaring that “the children of citizens of the United States, that may be born beyond the sea, or out of the limits of the United States, shall be considered as natural born citizens.” 1 Stat. 104 (1790).

For decades, constitutional scholars have debated whether a person is a natural born citizen eligible to serve as president, so long as he is a U.S. citizen at birth, regardless of the location of his birth. That debate ended as a practical matter in 2008, when the United States Senate unanimously approved a resolution deeming Senator John McCain eligible for the presidency. The resolution noted that “previous presidential candidates were born outside of the United States of America and were understood to be eligible to be President.” S. Res. 511, 110th Cong. (2008). The resolution also added that any other view would be “inconsistent with the purpose and intent of the ‘natural born Citizen’ clause of the Constitution of the United States, as evidenced by the First Congress’s own statute defining the term ‘natural born Citizen.’”

The Presidential Eligibility Clause does not explicitly cover those who serve merely as acting president (see Twenty-fifth Amendment), a constitutionally distinct office. Although Congress has imposed by statute, 3 U.S.C. § 19(e), the same eligibility requirements for service as acting president, that provision may not be required as a constitutional matter.