61 Million Immigrants in US, 15.7 Million Of Them Illegals

CAMPO, CA - JULY 30: US Border Patrol agents carry out special operations near the US-Mexico border fence following the first fatal shooting of a US Border Patrol agent in more than a decade on July 30, 2009 near the rural town of Campo, some 60 miles east of San Diego, California. 30-year-old agent Robert Rosas was killed on July 23 when he tracked a suspicious group of people alone in remote brushy hills north of the border in this region. Violence has been escalating in Mexico with fights between well-armed drug cartels and the army becoming common since Mexican President Felipe Calderon began his army-backed war on the cartels. Since the conflict began in late 2006, 12,800 people have been killed. Mexican officials charge that guns which are easily smuggled in from the US have flooded into Mexico where gun laws are strict. (Photo by David McNew/Getty Images)