The parallels between Brexit and 2016 US Presidential election are important. There were very high undecideds in Brexit, and they broke for Leave. Remain was "incumbency" yet didn't poll as well as the milieu of establishment does if it's favored. The same is true in this election. There are very high undecideds (and third party, which are also mostly undecideds). The "incumbency" is intensely unpopular, much moreso than Remain was. In the last month of Trump entering 3rd Act mode (acting presidential), undecideds have broken so remarkably for him that he gained ~10 points on Clinton.

If Trump doesn't blow past her and landslide this thing, we'll have rigging to thank.