It costs lives. Already a dozen people have died in the Arizona desert crossing into the country illegally. When will this stop? Mexico cares so much for their citizens that they refuse to fix their own country. If cheap labor is so important to the US economy why is not important to the Mexican economy?
It cost innocence. An illegal immigrant in Florida attacked and raped an 8 year old girl. He left her for dead and it is shear luck that she survived. This guy has been arrested multiple times before this attack and was never deported. Hmmm. What is wrong with this picture?
Seems like the answer to these problems is to make it easier for people to enter the US and stay here. Right.