We’ve had a lot of fun over the last couple weeks making fun of the idea that a committed terrorist would be dissuaded from their plans to commit mass murder (which is pretty illegal) by something as relatively trivial as gun control regulation. As we noted this morning, Abdehlamid Abaaoud was one of the most wanted men in all of Europe and he was somehow able to get numerous illegal fully automatic weapons, along with explosives, into the hands of the Paris attackers.

Any Republican who is actually defending Trump’s comments on the merits would do well to turn this kind of skepticism about the ability of American laws to deter terrorists on to the question of whether we should or could ban all Muslims from entering the United States.

Every country in which Muslims live has a religious minority of some size. Syria, it has been noted, has a relatively sizeable Christian population (although it has been decimated by genocide and the Syrian civil war). Virtually every Muslim-majority country has an equivalent group that lives (to varying degrees) in the shadows.

Anyone who thinks Trump’s proposal would deter actual terrorists from entering America must be unfamiliar with the doctrine of taqiyya, which extremist terrorists use to justify lying about their beliefs, but which mainstream Muslims would not interpret to allow them to lie just for the purpose of gaining entry in the United States.

Thus, the effect of Trump’s plan would be to completely remove peaceful Muslims who want to comply with U.S. law from coming here. On the other hand, it would permit any and all actual terrorists who want to come here because they could just lie and say that they are Christian, or Baha’i, or whatever.

This is exactly the same point conservatives make about gun control. A person who is inclined to disregard much more serious laws about terrorism and/or mass murder would not even blink about disregarding laws about legal gun purchases – or, for that matter, religious tests upon entering the United States.

We can argue over whether the proposal is good politics or not (I don’t think it is), and whether it’s constitutional or not, but one thing is certain: it would not work, at least to prevent terrorists from gaining access to this country.