The Secure Fence Act of 2006 granted possible funding to a, at the time, hypothetical fence, to be build on the border of the United States and Mexico. In 2008 the Reinstatement of the Secure Fence Act of 2008 was passed into law, which had the Department of Homeland Security (DHS) build 700 miles of fence (on a 1969 mile border, you can see how effective it is). Finally senator Jim DeMint tried introducing a “Finish the Fense” bill that would have required the DHS to complete the 700 mile fence (at the time they had only completed 34.3 miles according to DeMint’s site). Needless to say a lot of time, effort, and money has been invested into build a fence for nothing:
Two sophisticated tunnels probably built to smuggle drugs into the United States have been found on the border with Mexico.
The tunnels were more than 200m (656ft) long and had lighting and ventilation.
A US agent said their design “wasn’t something that an ordinary miner could have put together”.
More than 150 tunnels have been found criss-crossing the US-Mexico border since 1990; most were crude passageways.
That’s the funny thing about fences, you can simply tunnel under them. Sinking resources into building a fence to separate the United States and Mexico is nothing but wasted effort. The problem comes from the fact that smuggling drugs is a very lucrative business so great deals of resources will be spend on bypassing any mechanism designed to keep them. Mexicans crossing the border in search of work are also going to find ways of bypassing any barriers to entry because they stand the chance to make a great deal of money (compared to working in Mexico) in the United States.