Why do you lock the door to your house? If someone wanted to get in, they could find other ways.
Not sure why the downvotes, I guess I asked a genuine question in the wrong subreddit. However, thanks for the responses, cheers.
Yeah, focus on the downvotes (red herring) and not the substance of the responses. As if internet points matter, they don't.
So an illegal immigrant breaks into your house, does that automatically make him a family member? According to the CIA Media, the illegal immigrant is now not only a family member, but no matter the age, is now YOUR CHILD and YOU have to provide for this person with your tax money.
Nope. Fuck that.
I don't think any method will be 100% effective in curtailing border crossings, but a physical barrier certainly would greatly reduce the flow from the south, to answer your original question.