What I don't understand is, surely there should be a handful of guys in the Democratic Party who are in charge of strategizing and planning for campaigning in order to win elections, which is what they are supposed to do.
Part of this job must be having some contingency plans prepared in case something happens to your candidate (you know, the sitting president and most observed man in the world) that makes him unappealing for voters. Could be something predictable like a crisis at the Middle East or something unpredictable like the inevitable passage of time.
I would have expected first of all a good ol' spinning strategy. Then, a contingency plan focused on getting powerful endorsements from popular guys at the party who want to be the next in line (maybe a couple from swing states too) and will campaign for you given that carrot. That also helps focusing the message on the fact that you need a team to govern and that you have the best team. Unlike the other guy whose main collaborators are testifying against him. Last but not least, if these plans fail you should have a succession plan. Which means you should have been spending an important part of the last 4 years making your VP capable, popular and electable. Or your State secretary. Or your Chief of Staff. Or somebody else.
Yet somehow they failed to do all of the above. Looks like they were either stealing a living while expecting Trump and the Roe vs. Wade overturn would do the heavy lifting, which questions their competence. Or maybe they were too afraid to those in power to do their job, which questions the entire fabric of the party.