The presidential election of 2009 is the first in American history in which questions about the citizenship of both major party candidates were raised. Article II of the Constitution says that "No person except a natural-born citizen ... shall be eligible to the office of president." During the campaign, some argued that this disqualified John McCain, because he was born in the Panama Canal Zone where his father, a naval officer, was stationed. Also during the campaign, some conservatives raised questions about whether Obama was born on U.S. soil. Since Obama's election as president, those critics have spawned an entire movement of "birthers" who have displaced "tea-baggers" on the wingnut right.

But it doesn't really matter where McCain or Obama was born. In the first Naturalization Act of 1790, Congress, which included many leaders who had drafted the federal Constitution in Philadelphia, defined "natural-born" to include the children of American citizens born outside the United States. And Supreme Court interpretations of the 14th Amendment have established that children of foreign nationals born on U.S. soil are citizens of the United States. It is doubtful that the drafters of the 14th Amendment, which was designed to give U.S. citizenship to ex-slaves after the Civil War, intended to bestow citizenship on the children of foreign nationals in the U.S., but mistaken or not this interpretation has become settled law. There are, in short, three ways to become a U.S. citizen -- to be born on U.S. soil, to U.S. citizens or foreign nationals; to be born to one or more U.S. citizen parents abroad; and to be born a foreign national, but to become a citizen of the U.S. by immigration to the U.S. and naturalization according to U.S. law.

The Constitution excludes the third category of American citizens -- naturalized immigrants -- from ever being eligible to become president of the United States (or vice-president, inasmuch as the vice-president, who might inherit the office, must meet all of the qualifications of a president). Absent an amendment to the Constitution, Jennifer Granholm, the Democratic governor of Michigan who was born in Canada, can never become president of the United States, and the Austrian-born governor of California, Arnold Schwarzenegger, can never become terminator in chief.

How did this discriminatory clause get incorporated in the Constitution? During the Constitutional Convention in Philadelphia during the summer of 1787, John Jay, who would go on to co-author the Federalist Papers with Alexander Hamilton and James Madison and to serve as chief justice of the Supreme Court, wrote a note to George Washington, who was presiding over the convention: "Permit me to hint, whether it would not be wise and seasonable to provide a strong check to the admission of foreigners into the administration of our national government; and to declare especially that the command in chief of the American Army shall not be given to nor devolve on, any but a natural-born citizen." Washington agreed, writing: "I thank you for the hints contained in your letter." The convention passed the "natural-born citizen" requirement for presidential eligibility unanimously and without debate.

It might be assumed that the Founders were worried about foreign-born presidents partial to some particular ethnic nation. But in 1787, most of the states in the world were dynastic empires, where the ruling dynasties and aristocracies often were of a different ethnicity than many or most of their subjects. The Irish were ruled by the British Crown, the Slavic nations of the Balkans by the Austrian Empire's Habsburg family, and the Polish people were on the verge of being carved up among the Habsburgs, Hohenzollerns (Prussia) and Romanovs (Russia). To the south of the young United States, Spain and Portugal still governed their American colonies. True, there were already nationalist movements in Ireland and other nations that would eventually obtain national independence, but it is doubtful that the Founders were worried that a foreign-born president would support, say, Irish nationalists against the British empire. Living as they did in a world of aristocratic empires where monarchs and nobles sometimes moved among empires and kingdoms like CEOs moving among corporations, the Founders probably sought to prevent a foreign prince or nobleman from becoming commander in chief, as the Habsburg princeling Maximilian did in the 1860s, when he was temporarily and unsuccessfully installed by the French on the throne of Mexico. In other words, the "natural-born citizen" clause was probably motivated by fear of dynastic monarchy, not by fear of favoritism on the part of a foreign-born president toward one of the nation-states that obtained their independence only ages after the ink on the Constitution dried. 

One might still ask whether we should worry about the influence of ethnic or national lobbies on a president who was a naturalized immigrant. The answer is: Of course we should worry. An immigrant president who sacrificed the interests of the American nation to the country of his or her birth would be guilty of betrayal, if not treason. But in the case of ethnic lobbies, the most belligerent champions of this or that foreign nationality tend to be not immigrants but their second- or third-generation American descendants, who can play at identity politics without having to suffer the results.

What about dual or multiple citizenship? In today's world, many countries allow emigrants who become naturalized U.S. citizens to maintain their old nationality. The oath taken by naturalized U.S. immigrants to renounce foreign nationality is essentially a dead letter. To complicate matters further, a number of nations, including Israel, Ireland and Mexico, have "laws of return" that define members of ethnic groups living in the U.S. as citizens automatically, whether or not Jewish, Irish- or Mexican-Americans choose to take advantage of this status. It is troubling that foreign governments, by their own unilateral actions, have the power to divide the U.S. citizenry into different groups along ethnic lines, with some Americans eligible for benefits from a foreign state like the right to vote in its elections or the right to emigrate. But it is difficult if not impossible for the U.S. to do anything about such unilateral policies by other countries. However troubling this is in terms of democratic republican political theory, in practice it seems to cause few if any problems. Besides, a foreign-born president who technically was a citizen of another nationality, because of that country's own laws, would be under particular scrutiny by political rivals and the press for evidence of bias.

But similar scrutiny should be applied to a natural-born president biased toward a social class, or an industry, or a particular region of the country. There are many kinds of bias and partiality, and no reason to single out one kind in the Constitution.

The greatest threat to the U.S. has always come from sectional loyalties, not from foreign loyalties. The only significant attempt to destroy the United States came from Southerners, including the commander in chief of the Confederate army, Robert E. Lee, who was related to George Washington by marriage. Today the media plays up anything to do with race or immigration, but the polarization of the country along regional lines between red and blue areas is far more significant.

And some of the greatest traitors in American history have been natural-born citizens. Early American traitors included "natural-born" citizen Benedict Arnold, who defected to the British during the Revolution. Jefferson's natural-born vice-president Aaron Burr murdered Hamilton in a duel. Natural-born citizen Gen. James Wilkinson, who governed the Louisiana Territory after the U.S. acquired it, also alleged that Burr had joined him in a plot against the U.S. government. Before Wilkinson betrayed Burr to the Jefferson administration, the two were allegedly plotting to take over Texas, then ruled by Spain. In the 20th century historians discovered that Wilkinson was a double agent in the service of the King of Spain.

The benefit of barring the presidency from capture by this or that European princeling was far outweighed by the harm done by denying eligibility for the presidency to some of the greatest Americans of the founding generation, including Alexander Hamilton (born in the Caribbean) and Albert Gallatin (Jefferson's Swiss-born Treasury secretary). Another was the Scottish immigrant James Wilson, a neglected Founder who was one of the most brilliant theorists of popular sovereignty. They might not have wanted the presidency and if they had they might not have won it, but it was wrong to bar them from eligibility because they were not born in the United States.

Proposals to amend the Constitution to permit naturalized U.S. citizens to be eligible for the presidency often have been proposed but never have gone anywhere. The controversies about the citizenship of John McCain and Barack Obama make it clear that an amendment is long overdue. President Obama probably cannot propose such an amendment without pouring fuel on the fire of wingnut conspiracy theories. To his credit, Sen. McCain's campaign rejected using "birther" arguments against candidate Obama, having investigated the charges and found them groundless. Who better, then, to propose an amendment to the Constitution to open the presidency to all American citizens, native and naturalized, than Sen. John McCain?