“It’s possible [that some respondents won’t admit to supporting Trump], but I don’t think so,” said Bill McInturff, a longtime Republican pollster. “For two candidates with unusual negatives, the ballot by sub-group looks pretty traditional for what we’ve been seeing the last few cycles.”

“We won’t be able to say for sure until after Election Day, but it’s very unlikely,” said Mark Mellman, a longtime Democratic pollster. “Most of these kinds of theories don’t hold much water. People claimed primary polls were undercounting the Trump vote and they did not.”