Numbers comparison 2016 to 2020 on 17 August using RCP averages.
2016 Clinton 43.5%, Trump 37.3%, third party 11.4%, undecided 7.8%
2020 Biden 49.8%, Trump 42.3%, third party 4.0%, undecided 3.9%

Roughly, Biden is up by 6 over where Clinton stood back in 2016, Trump is up by 5 from where he stood in 2016. Third Party down by 7 and undecided’s down by 4. Unlike 2016, a lot more folks have made up their minds on who to vote for this year. There isn’t that big pool of voters in the third party/undecided column, 19.2% for Trump to pull from to overcome Biden’s 7.5-point lead, only 7.9% as of today in the third party/undecided column. In 2016 Trump had a pool of roughly 19% to pull from to overcome Clinton 6-point lead, this year that pool is 8% to overcome a 7.5-point Biden lead. That in my opinion is the huge difference between 2016 and 2020.

This has nothing to do with the horse race numbers, Clinton’s 6-point lead vs. Biden’s 7. It has everything to do with the pool, the number left to overcome those lead. For me, the most important numbers are 19.2 vs 7.9. In 2016 Trump didn’t need to switch one Hillary supporter to his side, he had that huge pool of 19.2 to draw from. In 2020, Trump needs to change some Biden supporters’ minds, he needs to convince them to jump from Biden to him as his pool of third party/undecided’s isn’t big enough without Trump swaying some Biden supporters away from him. This he didn’t need to do with Clinton supporters in 2016. Which made making up the deficit much easier and more doable. It will be much harder this year, maybe, just maybe depending on what happens between now and election day, maybe not doable at all. Time will tell.

https://www.realclearpolitics.com/epolls/2020/president/us/general_election_trump_vs_biden-6247.html

https://www.realclearpolitics.com/e...vs_clinton_vs_johnson_vs_stein-5952.html

It's high past time that we start electing Americans to congress and the presidency who put America first instead of their political party. For way too long we have been electing Republicans and Democrats who happen to be Americans instead of Americans who happen to be Republicans and Democrats.