by Rod D. Martin
May 7, 2015

The meaning of “natural born citizen,” as used in the United States Constitution, has nothing to do with the medical procedures (or lack thereof) involved in one’s birth. Rather, it has to do with whether a person was entitled to citizenship from the beginning of his or her existence, as opposed to choosing to become a citizen at some later point.

Because of the need to establish the citizenship of freed slaves, the 14th Amendment established a “jus soli” standard in the text of the Constitution: that anyone born in the United States and subject to its jurisdiction is thereby a citizen. The “subject to its jurisdiction” part leaves some wiggle room. For example, the child of a foreign diplomat, born in the United States, would not be entitled to U.S. citizenship. This means that Congress could potentially remove the automatic right of citizenship from the children of illegal aliens, on the ground that they are rightfully subject to some other nation’s laws. But this is a different discussion.

U.S. law has also always held to the “jus sanguinis” standard, which is, that the children of one or more citizens are thereby citizens as well. So under that standard, for example, the child of a U.S. serviceman born overseas because of his parent’s deployment is himself a natural born citizen, regardless of the geography of his birth, of whether both of his parents are U.S. citizens, and of whether his parent(s) were themselves naturalized or natural born.

However, note that this jus sanguinis portion is a statutory, not a Constitutional, matter. As a result, Congress can create exceptions, and it does. The intricacies are codified at 8 USC § 1401, as follows:

1. If the child’s parents are married and both are U.S. citizens, the child is a natural born citizen, but only if at least one of the parents has been resident within the United States at some point in his or her life prior to the child’s birth.

2. If only one of the child’s parents is a citizen, but the other is only a U.S. national, then the child is a citizen so long as the citizen parent has been resident in the United States continuously for at least a year at any point prior to the child’s birth.

3. If only one of the child’s parents is a citizen, and the other is a foreigner, the child is a citizen so long as the citizen parent has been physically present in the United States for a cumulative total of at least five years prior to the child’s birth, but with the caveat that two of those years must have been after that parent’s 14th birthday.

4. If the child’s father is American and is not married to the child’s non-American mother, the child is a citizen if the father has lived in the United States continuously for at least one year, but only if the father also acknowledges paternity (or if paternity is established by a court of competent jurisdiction) and agrees to financially support the child until the age of 18. Moreover, the child is not a citizen unless these things take place prior to his/her 18th birthday.  This provision, however unfair it might seem, was enacted to prevent a flood of illegitimate Korean and Vietnamese children into the United States after those respective wars, and again, however unfair it might seem, all of this was upheld by the U.S. Supreme Court in 2001 (Nguyen vs. INS).

5. If the child’s mother is American and is not married to the child’s non-American father, the child is a citizen so long as the mother has lived in the United States at least one year prior to the child’s birth.

This last bit is important with regard to the ongoing “birther” debate, which is most prominent with regard to Barack Obama (raised originally by supporters of Hillary Clinton, I should add), but which has also been applied to John McCain (born to two American parents in the then-Panama Canal Zone, sovereign U.S. territory at the time), Ted Cruz (born in Canada to a natural born U.S. citizen mother and a Cuban immigrant father who naturalized later), Marco Rubio (born on U.S. soil in Miami, Florida, but whose parents were born in Cuba), Barry Goldwater (born in the Arizona Territory, not yet a state), and (among others) even Mitt Romney (born in the United States to two American parents, but whose father was born in Mexico).

The unique twist in the Obama case, if there is one at all, is the suggestion that Obama may have been born to a U.S. citizen mother while in Kenya. If this were true, the statute today would be no problem for him: he would clearly be a natural born citizen. However, prior to 1964 (Obama being born in 1961), the U.S. citizen mother giving birth abroad also had to live in the United States for at least one year after her 18th birthday and prior to the child’s birth. If Obama had in fact been born in Kenya, his mother would have been just nine months past her 18th birthday, and thus he could not have been a natural born citizen.

Again, this requirement was repealed in 1964. However, the holding in Nguyen vs. INS gives us every reason to believe that if it were ever proved that Barack Obama was born in Kenya, the Court would not retroactively apply that repeal to his case. I very much hope I am wrong in that. The statute was changed for a reason: with the increase in female service members in the early 1960s, it became increasingly clear that the statute as then worded had great potential to create enormously perverse situations, in which children born to women putting their lives on the line for their country might be excluded from citizenship by an accident of the calendar. Congress wisely changed the law, but clearly too late for some. And while this answer is not intended as a discussion of the Birther issue per se, the issue rarely addressed is that if Barack Obama were excluded from natural born citizenship, it would only be because his mother got on an airplane at the wrong time.

That’s no way to run a country.

This article originally appeared as an answer on Quora.