The borders of a nation are set to stop those who would bring weapons against it

You set protections on your borders to stop those who would bring guns and canons against it. If an enemy comes without a weapon, he is not a enemy to fear.

So, think on the immigrant. Think on the popular sentiment that a nation without borders is not a nation at all. Think on what borders are for, and who they were meant to stop.

The simple immigrant or the foreign power? 

 The immigrant comes not with mortars and rifles. He carries not a weapon at all. If his is an assault, if his is an invasion, it is far from the assaults and invasions borders normally defend against.

The immigrant comes in peace. A foe without a weapon is hardly a fear. We should wonder why we even see him a foe. We should give second thought to the notion these are our enemies.

If you set your war against immigrants, you fight against shadows. You take the poor and the starving and homeless and oppressed, and you suddenly see in them an invading army.

If you see the poor as your enemy, you are as one who runs from the shadows. Your borders? You make them a hedge against ghosts.