People really get sidetracked on the issue. Mainly because the liberals don't want closed borders, because they're told they don't want it. The political side is really two pronged: 1) the left lost the blue collar voters so they don't care about protecting them and need to manufacture more votes 2) they would see a barrier as a win for Trump and they don't want that.
The truth of the matter is that border security is just like your house. Ask any police officer how to protect your home and they all say the same thing. Criminals are lazy, so make it harder to break into than your neighbors: lock your doors, add exterior lighting, cut your shrubs, etc. The metaphor here is to make it harder than it's worth to try to break in. Comprehensive border security is more than just a wall. It's layers upon layers of motivating people to not try. This includes making clear laws defining citizenship that prevents citizenship by simply being born here.
Back to the house metaphor. When people break into a house, they typically don't break in thru a wall. They go thru a door or window. Which is why alarm companies put senors on doors and windows and why people who are serious about security are buying hurricane glass, more secured doors, and harder to breech locks. It's layered even on a residential level. Security camera systems are becoming much more prevalent.
A barrier is necessary to funnel the activity to other points, like the ports of entry, where there can be a more efficient use of our resources.
Now if you want to have an actual discussion on the merits of border security, that would be a longer post. So just watch what your Dems have said in the past about it before you post.
Best Posts in Thread: Who will the closure hurt more?
Drugs are typically discovered at ports of entry for two reasons; 1) They are at population centers which means dealers are close to the demand, easy money. 2) Population centers are near highway systems so it's easier to transport contraband throughout the country.
On the border, Trump turns political in making case for his wall