First, I think you misunderstand poll margins of error. For example, the NYT poll is +-4 for each candidate. Meaning it could swing a total of 8 points.

That isn't anything new.

"In a new paper with Andrew Gelman and Houshmand Shirani-Mehr, we examined 4,221 late-campaign polls — every public poll we could find — for 608 state-level presidential, Senate and governor’s races between 1998 and 2014. Comparing those polls’ results with actual electoral results, we find the historical margin of error is plus or minus six to seven percentage points. (Yes, that’s an error range of 12 to 14 points, not the typically reported 6 or 7.)"

(written before 2016 election) https://www.nytimes.com/2016/10/06/upshot/when-you-hear-the-...