According to a POLITICO/Morning Consult study conducted by Morning Consult this past weekend and released Thursday, a hidden army of Trump voters that's undetected by the polls is unlikely to materialize on Election Day.
The study — which was composed of interviews with likely voters conducted over the phone with a live interviewer, and other interviews conducted online without a personal interaction — showed only a slight, not-statistically-significant difference in their effect on voters’ preferences for president.
Nate Cohn writes at The New York Times:
Mr. Trump may yet win this election. But if he does, it probably won’t be because of a huge influx of Republican-leaning “missing” voters.
There has been no surge in registration among white voters since 2012, and the white voters who have joined the electorate are younger and likelier to support Mrs. Clinton than those who were already registered.