[concerned about politics]

Did you know a thermal nuclear weapon is no bigger than a soccer ball? You've heard about the underground tunnels running from Mexico to the U.S.? The trucks that come to America every day to do commerce? For the right price, a soccer ball sized bomb could wipe out most of Arizona. It would make Chernobyl look small because of the power plants located there.
Open borders and a massive influx of foreign illegals who believe the south west belongs to them is not a pretty picture.
This is a military issue, not a political one.

[tobyhill]

It's a border line "military issue" but definitely a legal issue and for that reason any border state Governor can call the National Guard to control the border.