The Wall Street Journal had an interesting article today about illegal immigration slowing. The numbers are presented below. The article highlights that the illegal population is estimated at 11 million today, which is 8% lower than it was in 2007. No matter what one's stance is on illegal immigration, an outflow of any type of worker from the US economy is not a positive for GDP.
Of course, before the WSJ tackled the subject, South Park did--a recent episode centers on illegals leaving the US to go back to Mexico because the US has become so much worse than Mexico.