Donald Trump threatens this peace by raising the prospect not only of sending his supporters, unsupervised, into polling places (likely in minority neighborhoods). This can lead to voter intimidation on election day. He has also backed off his earlier, somewhat ambiguous statement that he would support Hillary Clinton if she won. Now, speaking to the New York Times he made a chilling statement:

Mr. Trump, aiming to unnerve Mrs. Clinton, even indicated that he was rethinking his statement at their last debate that he would “absolutely” support her if she won in November, saying: “We’re going to have to see. We’re going to see what happens. We’re going to have to see.”