Rich Lowry: Buy Trump off with his border wall

There is a very easy way for Democrats to get major concessions from President Donald Trump on immigration: Give him his wall.This is the key to a deal codifying the Deferred Action for Childhood Arrivals program, the Obama-era de facto amnesty for a segment of so-called Dreamers. All it takes is giving Trump a plausible start to the wall that the president can then, in his inimitable way, promote as the greatest structure built on a border since Hadrian began his famous handiwork at the norther