20,000 shoulder-fired missiles, each capable of taking down a commercial airliner, are missing from Libya. That is all the reason needed to stop the free flow of people across the Mexican border.
A secure border is coupled to illegal immigration so that liberals have a bargaining chip, a hollow one. As always liberals (and Ms Chavez it seems) are not interested in a secure border. Rather they seek to grow the class of Democratic voters dependent upon the federal government.