The only “Sanders problem” the Democrats have is they don’t recognize him and his movement as both the way to get back in touch with their New Deal roots and as the way forward for their party to remain viable in the 21st century.
Three decades of neoliberal slippery slope policies have made the Democratic Establishment akin to the 20th century Republicans in terms of economic and foreign policy with just enough “woke” signaling on culture war issues to keep voters somewhat in line.
Thing is, many of us voters worked from outside the Washington DC system to pass things like legalization of recreational marijuana and gay marriage via ballot initiatives so one really has to ask what the Democrats have done for the People recently?
This is why Bernie Sanders resonates. He actually cares about issues facing the working and middle class and isn’t merely pandering to us while taking Wall Street and billionaire money a la the rest of the field.
Thus, the only problem for the Democrats is not recognizing that the way they’ve been doing things is no longer viable. You can’t simply win on “we aren’t them.” You have to tell us what you are and give us reasons to believe you mean it.