The Citizenship Clause of the 14th Amendment states: "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."
and subject to the jurisdiction thereof = legal citizens and legal green card holders.
And before you haters try to argue, get some facts:
Enough! Feds Raid 20 Chinese Immigrant “Birth Hotels” in Los Angeles
^^ Clearly abusing the system, and common-sense Americans have had enough.