"I believe in small government"

It is typically authoritarian countries that erect border walls, and they are ultimately used to keep people in. One out of every 9 prisoners on death row are exonerated after evidence revealed their innocence. The death penalty, since its establishment, has never worked ever as a deterrent against crime, and states without it even have lower murder rates. Literally no answer for torture, but it's unconstitutional and you folks are supposed to care about that.

Walls have been effective barriers to lawless marauders throughout history. The Great Wall, Hadrians wall, the limes in Germany and western France. When your country attracts people you must have a form to keep from being overwhelmed so that you can assimilate the new arrivals into the culture. Of course if your goal is to supplant that culture, then yes, no enforceable borders and The call of free healthcare and education will do the trick to overwhelm the system and create the conditions for the cultural revolution you are looking for.

There would have been no shame in saying you don't have an argument.

Brilliant and thorough justifications for each.