It is embarrassing even to embark on such arguments. To treat “no Muslims allowed” as a serious idea is to give credit to what is little more than a clever stunt by a man who saw Ted Cruz beating him for the first time in the Iowa Monmouth poll and five hours later decided it was time to seize the stage again.

This got the thinkers going again. National Review’s Andrew McCarthy, whom I (otherwise) hold in considerable esteem, spent 1,000 words trying to tart up the ban in constitutional and statutory livery, stressing — hilariously — that he is dealing with the Trump proposal “in its final form.” As if Trump’s barstool eruptions are painstakingly vetted, and as if anything Trump says about anything is ever final.

Take his Syria policy. In September, he said we should wash our hands and just let Russia fight the Islamic State. Having, I assume, been subsequently informed that Vladimir Putin’s principal interest — and target — is not the Islamic State but the anti-Assad rebels, Trump now promises to “bomb the s—” out of the Islamic State.

I’m sure there’s a Trump apologist out there working to explain the brilliant complementarity of these two contradictory strategies. Just as a few months ago there was a frenzy of learned scholarship about the constitutional history of the 14th Amendment following another Trump eruption — the abolition of birthright citizenship.