William Saletan disproves Donald Trump's repeated claim that most Americans support the building of The Wall. Trump will never admit it, of course. For Trump, there is no proof possible that he is wrong on some supposed fact or that he does not have the majority of the nation solidly behind him.
Saletan doesn't mention it but a lot of those who did support The Wall at the time of Trump's election did so under the belief that Trump had some way to force Mexico to cut a check for the entire cost of the project. I'm in favor of a lot of things until I see what I'm going to have to pay. And yes, the case can be made that Trump didn't explicitly say Mexico would make a direct payment (except he kinda did) but a lot of people sure thought that was the idea.
A question I'd like to see him asked is: "You keep saying The Wall is desperately needed. Is it so desperately needed that the U.S. should foot the full cost even if there's no chance of Mexico paying any of the cost in any way?"
And another is: "Would Donald Trump the real estate tycoon commit to fund a project if he knew as little about it as we know about what The Wall will cost, what it will be made of, what it will cost to acquire private real estate to build it on, who will build it, when approximately it will be completed, what will be the ongoing costs of upkeep on it, etc.?"