Are polls actually underestimating Donald Trump's support?

It turns out that a non­trivi­al share of these same work­ing-class, anti-im­mig­rant voters won’t tell a live per­son who they sup­port but will share their true feel­ings when their sup­port is secret — like on Elec­tion Day. This is no sur­prise: Sup­port for im­mig­ra­tion and glob­al­iz­a­tion are per­haps the only polit­ic­al sentiments that unite elites from both busi­ness and the academy, from right and left. Openly sup­port­ing an anti-im­mig­ra­tion can­did­ate can risk so­cial op­pro­bri­um, ri­dicule, or worse. In oth­er words, for every group of vo­cal Trump sup­port­ers, there are prob­ably a lot more who just don’t ad­vert­ise it. [National Journal]