1) Even with poll tightening for Election Day Eve 2016, the following overestimated the Dem:

Econ/YouGov: Clinton +4%
ABC/WP: Clinton +3
Fox News Clinton +4
NBC News/WSJ: Clinton +5
Monmouth: +6
CBS News: Clin+4
Reuters: Clin+5

Average: Clinton +4.4
Actual Result: Clinton +2.1

2) Note:
1. All overestimated Hillary.
2. The average overestimate was 2.3%.

Even with their best effort, Big Media pollsters still favored the Democrat by around 2 points.

(Note: if one added IBD/Tipp which had Clinton +1 the average was Clinton +4 and a 1.9% overestimate)

3) The above does not mean Big Media will overestimate Biden by 2% before Election Day this time, but so far we have not seen evidence they have adjusted.

POINT: Based on past performance, Big Media could overestimate Biden by at least 2 points on Election Eve 2020.