Just how secure is Gang of Eight border security plan?

The bipartisan Gang of Eight has released its new comprehensive immigration proposal. Before the bill was made public, supporters said it would require the government to maintain 100 percent surveillance of the U.S. border with Mexico and catch 90 percent of those who try to cross it illegally. They spoke very clearly: 100 percent surveillance and 90 percent apprehension.

Now the bill is out, and the wording is not quite as clear. The bottom line is that it does not mandate 100 percent surveillance and leaves questions about what 90 percent apprehension actually means.