Ari on MSNBC wasd just talking about Hillary polling higher than Joe is at the same time in the

[Ms. Toad]

65. National polls predict the popular vote, not the electoral vote.

Electoral votes are state by state, and are - by and large - winner takes all. That's why you can have a popular vote winner who does not become president.

If the national poll spread is based on Biden doing really really well in large blue strongholds, it hides the smaller - much closer races in the states that are critical to winning - where the electoral vote isn't split 50-50 (as the national polling treats them), but winner take all. So if Tump wins those votes it is as if he won 100% of the votes in those states - even if he only won by 1 vote.

So - just to simplify matters:

Let's say we have 5 states - each with 10 electoral votes and equal population.
State 1: Biden ahead 80:20
State 2: Biden ahead 75:25
State 3: Trump ahead 51:49
State 4: Trump ahead 51:49
State 5: Trump ahead 51:49.

The popular vote, if it matched the polls, for this 5-state country would show Biden ahead 60.4:39.6 - a 20.8% lead
The electoral vote would award the presidency to Trump based on his 30 electoral votes (states 3-5) against Biden's 20 (states 1 & 2)

That is obviously a gross simplification - but it should illustrate the point as to why the national poll does not necessarily predict the electoral vote.

The quality of the polling is not the issue - we don't elect our president based on the national popular vote. We elect him based on electoral votes. Those are inherently state-based, and they are winner take all so (as illustrated above) if his lead is large and in the wrong states he could lose spectularly in the electoral college where slim margins make a ginormous difference in the electoral college vote.