1) Re-inspire the original base -- working people, middle class, unions
(people actively spurned by the DNC in 2016... remember Chuck Schumer's immortal prediction: "For every blue collar vote we lose in the rust belt, we'll win two Republican votes in the suburbs." Not.)
2) CHANGE DNC SOP (standard operating procedure) in order to pursuade the 14 million people who LEFT the Democratic Party in 2016 that there are good reasons to return to the Party
(HINT: "We're not Trump" is not good enough. It did not work in 2016. It will not work in 2020. Don't try the same thing and expect a different result.)
3) Reject Corporate Rule of the party -- no more dark money, no more giant corporate donors pulling the strings
(Period.)
4) Complete transparancy -- make public all income and all expenditures
(Nothing less will restore our faith.)
5) Aggressively purge the party of Conflicts of Interest
(two examples: Lobbyists serving as voting members of the DNC who influence policies, resolutions and endorsements that serve their corporate clients, and Consultants serving as voting members of the DNC who make hundreds of millions in fees for contracts they vote to authorize themselves)
6) Walk like Bernie, Talk like Bernie, Make Policy like Bernie.
Establishment Democrats will fight against the above with tooth and nail.
They would rather lose to Republicans than win by giving an inch to the progressives, because under their current system, they rule with absolute power and they are reaping vast wealth from the Democratic Party machine.
Democrats cannot defeat the corruption of the GOP by being equally corrupt, yet that is the direction which the DNC has gone for the past 30 years of right-ward drift (read LISTEN, LIBERAL).
Before we are ready to win in 2020, we need to get our own house in order.