That isn't true:
Overall, 34% of registered voters identify as independents, 33% as Democrats and 29% as Republicans. The share of voters identifying as Republicans is now the same as it was in 2016, after having ticked down in 2017 (June 2020).
The gender gap in party identification remains the widest in a quarter century.
www.pewresearch.org
Trump initially lost Lincoln Project-type Republicans (all 12 of them) but has since made up the gap. And when the dust settles and we get better numbers from 2020, the proportion is almost certain to have further increased, especially among Hispanic voters.
The Biden campaign does not believe in door-to-door campaigning. It has nothing to do with Covid 19. They didn't do it in the primary either, which worked because, to a far, far, far greater extent than Republicans, Democrats believe whatever the television tells them.
(for a single image that explains American politics since 2016, look no further^)
But with a general rather than primary electorate, this is a mistake.
Democrat grassroots groups in the Twin Cities suburbs, Milwaukee/Madison, Detroit/Dearborn, and especially the Lehigh Valley and suburban Georgia have been building
for years, picking up from where Obama abandoned them and facing active hostility from day one from the Party itself since 2016, in the first four instances.
It is a good thing that House Democrats were unsuccessful in seeking to destroy Ilhan Omar by breaking their own anti-AOC rules against contesting incumbents, because although she has no future beyond the House, her team probably saved Minnesota.
Having swung the balance for Joe Biden, they are now being scapegoated by lazy, corporate, for-life Democrats like Spanberger or Connor Lamb who lost because they offered voters nothing and would not know how to campaign if they tried, despite getting the Presidential candidate they all demanded. As the graph above, this excuse will serve its purpose and will likely enable them to be promoted upwards, where, along with Robby Mook's computer, they can blame socialism again in two years' time for overseeing the comprehensive kicking that the Dems are going to face in the midterms.
I mean, just like what those succubuses in The Squad made poor Connor Lamb do!
It is a cliche because it is true: Whereas Republicans fear their grassroots, Democrats hate their grassroots - even though they are the only people who know how to get corporate Democrats elected.