So one of the political lessons of the primary election season is how badly polls have been wrong. Comrade Abdul El-Sayed in Michigan was supposed to win by more than 20 percentage points, but instead barely escaped by a thin cat’s whisker.And the extremist Francesca Hong in Wisconsin was also supposed to win by 20 points or so. But she lost by an even thinner cat’s whisker.And there are plenty of other examples. Where am I going with all this? Well, all these polls show President Trump’s supposed unpopularity on Iran or the economy or the much-abused term affordability may turn out to be very...