When we have another 9/11 type attack, I am confident that our southern border will look similar to the Israeli fence. It's an absolute shame that this is likely what it will take before anything will be done though.
U.S. Constitution Article 1 Section 8 Clause 15:
"The United States shall guarantee to every State in this Union a Republican Form of Government,
1. The act of invading; the act of encroaching upon the rights or possessions of another; encroachment; trespass. [1913 Webster]