All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside.
The Federalist Blog explains what it means.
- Click here for the post.
It's worth reading in full, but this captures the basic argument:
Because the purpose of the Fourteenth Amendments first section was to end the denial of those fundamental rights that belong to all citizens by virtue of their citizenship under Article IV, Sec. II of the U.S. Constitution was imperative to first define citizenship of the United States. Otherwise, a State could refuse to recognize newly emancipated slaves as citizens by withholding the right to sue, make contracts, due process, purchase property, etc. Therefore, the Fourteenth Amendment acts to recognize all persons as citizens who do not owe allegiance to some other government when naturalized or born.
The last sentence is the kicker, and it applies to - for example - children born of foreign ambassadors and to members of an invading army. Not only are they not allegiant to the United States, they are not subject to its rules - though that's probably more true of the diplomats. Those who argue that the children of illegal immigrants should not be covered under 14th Amendment raise the question of allegiance, but there still remains the question of whether they are subject to the laws of the state. They are. So that complicates things.