The race has remained remarkably stable for months.
When you look at the average of all the polls, Hillary has been very steady at 42% while Trump has been very steady at 38% for nearly the entire race, except for a 3 week period surrounding each candidates convention.
When you look at the polls ... the race doesn’t even appear to have started. Both are still exactly where they were at the start.
Only among "likely voters," which is how most polls are taken, using people who have voted in at least 2 of the last 3 national elections.
Such polls ignore the nearly equal number of those who haven't voted in years, and those who have never voted. Nearly all of whom are voting Trump (he alone is the reason they're voting this time!), and none of whom these polls reflect.