Not saying there were not missteps in both the primaries and the general election, but Dems need to determine what they were and how to improve the party for all factions. That's why new leadership is needed. But, the Dems must not hand the GOPers the next three election cycles on a silver platter. Which is what will happen if they become the party of extreme liberalism.
Will have to wait and see, but I don't believe anyone is asking for one faction to submit to the other. There are actually many different factions in the Dem Party.
It appears to me that the "progressive/liberal" wing is demanding that the "establishment" faction submit to them in all areas. If not, they bolt the party.
One problem the Dems have that the Republicans don't, is that basically the GOPers have too factions - extremists and very extremist with corporationists manipulating both.
Sanders comments today about how the DNC elect their leaders is very telling. Additionally he stated that he would not provided the DNC the list of his donors.
To me both factions are digging in and making demands. Therefore at this time I don't see the two factions coming to terms. Instead, like we saw with the DNC leadership vote, in the 2018 Dem primaries each faction will support their own candidate who will relentlessly attack their fellow Dem challenger and whoever wins will be weaken (e.g. having to spend money to win the primary), as well as not getting the required support from the losing faction in the General election. All of these factors just increase the odds of the GOP candidate winning in the general in all put the blue\blue states.