Wow. Good thing you're patient.
I think many Americans would be uncomfortable with a wall, but supportive of a fence. Or at least a virtual fence with in many ways would be more secure than a traditional fence.
In any case, you are absolutely right that it is a serious issue...but also a complex one. I used to think I knew exactly what we should do, but the more I study the issue, the more I realize that it is incredibly difficult to tackle and that there are no easy answers.
Human beings tend to do what they want to do, despite everything. We are a fairly tenacious bunch. That makes things like this much harder to solve.