If Paul wants to use restrictionism to fight Islamic extremism, he’d have to use a pretty extreme kind that slams the door completely on the Muslim world. This means denying Muslims not just opportunities to study — but also travel — in the West lest they enter the country through tourist visas and then not leave, something that some of the 9/11 hijackers did, as Paul constantly reminds us. But of course, not all Muslims live in the Arab world. They also reside in Asian countries such as India, Malaysia, and Indonesia, which means that travel from these nations would also have to be restricted.

This kind of bunker mentality would only deepen geopolitical hatreds, a recipe for making the West less safe and less free. Why? Because it would involve giving Western governments vast new powers to control the border in order to maintain the right mix of religions. 

Rand Paul is trying to distinguish himself from his Republican buddies by exposing the draconian nature of the twin wars on drugs and terrorism — especially the injustice and discrimination they’ve unleashed on minorities. He should be the last one setting the stage for a war on immigration.