One of about every 12 babies born in the United States in 2008 was the offspring of unauthorized immigrants, a Pew Hispanic Center study released Wednesday concluded.
According to the study, an estimated 340,000 of the 4.3 million babies born in this country that year had parents who were in the United States without legal documentation.
The 14th Amendment to the Constitution stipulates that those children automatically become U.S. citizens, but some members of Congress are pushing to change that provision. That effort - rooted in the debate over illegal immigration, particularly of people from Mexico - has created some controversy.
"This has got a lot of attention in the past weeks," said Jeffrey S. Passel, the study's author. "The idea was just to put a number on it."