We changed candidates very late in the process - that creates a very difficult challenge. See e.g. Paul Wellstone's death
We overestimated the excitement of the race
We did not have TIME to help the electorate get to know the candidate
Misinformation was too rampant and we couldn't counter it

This was a failure of education that started 60 years ago when the NatCs started taking over our school boards and dumbing down our schools. We need to examine and understand their strategy and replicate some of it.

The Biden/Harris switch so late was an immediate hamstring.

DU is a collection of Dems who are highly engaged politically and active. This is not the norm, yet we expect it to be. Most people are pretty tunnel visioned on just the kitchen table basics, not the wider social issues. You start straying from the kitchen table, your audience narrows further and further with those who just aren't as politically engaged as DU people.

YES. You are correct. In the aftermath I am stunned by the number of people who DID vote for Harris who still don't grasp that this was not a normal election!! If we, collectively, didn't understand the enormity of the differences how could we expect the rest to understand and be motivated about it?

But not so fair and square when it comes to voter suppression, purges, etc.

We have a problem that a large percentage just could not bring themselves to vote for a woman as a Leader.

And many others would vote for a lying convicted felon over a woman. Bald faced lies work if you make enough people believe them, and there are a whole cadre of billionaires paying to promote the lies.