(The right lies Tijuana, Baja California, and on the left is San Diego, California. http://en.wikipedia.org/wiki/Mexico%E2%80%93United_States_border)
The image of Mexican-American is shaped by boarder since Treaty of Guadalupe Hidalgo in 1848. The border lands covering the states of Texas, New Mexico, Arizona, and California. The boarder today is continuous challenged by illegal immigration and drug smugger.
U.S. Customs and Border Protection holds a key position. Mexican-American boarder is in middle of criminal traffic: drugs made by drug cartels in Mexican have to export into market in the U.S., and than the revenue from selling drug (mostly in cash) also have to transfer into Mexico, or buy weapons from gun shops in the U.S. have to transport into Mexico for drug cartels.
Although drug cartels tried to break the security for smuggling their drugs into the U.S., Customs and Border Protection intercepted most of the traffic by advanced sensors to detect the drugs hidden in varies of method of transportation.
Illegal immigration is different. Because the boarder lands in MexAmerica is hot, dry weather. Many of illegal immigrates risk their live to cross the boarder into the U.S.. They usually lacks water, food, and clothes to cross desert's hot daylight and cold night time so missing and death are very common for illegal crossing.
http://www.nytimes.com/2013/05/21/us/immigrant-death-rate-rises-on-illegal-crossings.html?_r=0