Giving America away:

‘Illegal Immigrants Bear 8% of Children Born in the U.S.
As discussion over whether to end birthright citizenship intensifies, a new study of Census Bureau data reveals that 8 percent of children born in the United States in 2008 were parented by illegal immigrants.
The Pew Hispanic Center, a project of polling organization Pew Research Center, finds that, of the 4.3 million babies born in 2008, roughly 340,000 were born to undocumented aliens. This is double the percentage of illegal immigrants in the U.S., owing in part to the fact that the illegal immigrant population is largely comprised of men and women at birthing age.
In addition, high birthrates among undocumented aliens give that population a similar share of children in the U.S. The study finds that children born to illegal immigrants account for 7 percent of the total population of people under the age of 18, or 5.1 million children. Four million, or 79 percent, of those children were born in the United States, making them U.S. citizens.’         source