Which is only one way to address the problem. And in my view, the least desirable, not to mention the most expensive option.
It might work, but if you really want the tide to be stemmed, it has to be done by the Mexican government. They won't do it because we make them pay no price. And they use it as "steam control" to keep their useless political sysytem afloat.
A quick withdrawal of all benefits to their government unless they stop the nonsense is a better first approach, IMO.