For all practical purposes there is an “open borders” policy in the United States with respect to Mexico, since so much of the southern border is under-fenced and lightly patrolled, while the government declines to enforce our immigration laws. Whether the reason is political correctness, or a fear of being called racist, or a reluctance to engage in “profiling”, or a favor to agribusiness, immigrants can cross the border from Mexico with virtual immunity from federal interference. for more click here