Hey, Can We All Agree on Ending Protectionism for Doctors and Dentists?

The response to Donald Trump's ban on Muslim immigrants has been reassuring. Millions have people have acted in various ways to express their opposition to this blatant act of bigotry. But as part of this story, we are being told that immigrants everywhere and always benefit all workers.

Far be it from me to criticize this great wisdom, which we can find in this Wonkblog post by Christopher Ingraham. So let's pretend that the people making this assertion have a shred of integrity. How about g...