This immigration ban - like its predecessor - is wrong, backward, unnecessary and possibly unconstitutional.  It will hurt America economically, culturally, socially and further erode its already beleaguered reputation on the world scene. 

But I have not seen a convincing argument yet - including the one in this article - on how or why it will make America more prone to terrorism. By that logic, the U.S. would be at it most vulnerable if it closed its borders completely. 

There is enough to fault Trump's racist, xenophobic, narrow minded policies without resorting to unprovable speculation.