It's an interesting question.
Most House candidates dubbed "progressive" by the media - and thus exoticised and gawked over as such by the media - did not do especially well. If we are being honest with ourselves, we should acknowledge this
(Beto - while someone which people who devour the West Wing and Pod Save America assume to be progressive simply because he is handsome, relatively young, and charismatic - is bland white stale Wonderbread in policy terms). And there is also a big difference between defeating a long-term mostly-absentee incumbent in Queens, and winning in, say, West Virginia (which until after Clinton, was one of the most Democratic states in the Union). It remains to be seen.
Americans, even Republicans, overwhelmingly support progressive policies. But what Real Americans do not often support are candidates which the media brands and packages as "progressive", especially progressive Democrats. It is akin to trying to sell Pork Rinds at Kroger, but hidden inside packaging for organic artisanal kale. Ewww.
For the most part, they (rightly) dislike the Democratic Party, almost as much as they dislike the Republican Party. Though it led people who devour the West Wing and Pod Save America to paroxysms of agony, Bernie's decades of distate if not open contempt for the Democrats was critical to establishing his credibility with swathes of Real America, as were his decades in the (literal and figurative) wilderness, spurning money and influence and corporate concessions out of honour and principle.
What Democrats should really do is a make a show of disbanding the Party altogether, and starting anew with a different name and message. If any institution in the country is crying out for a rebranding, it is the Democratic Party.
But given that this will never happen, they could do worse than to pair someone just like AOC with a grizzled Ron Swanson type - Jim Webb with brain transplant - who plausibly looks like he enjoys ride-mowing flora, automatic-weaponning fauna, satiating America's lust for spilling overseas blood, and consuming fried corn-derived merchandise, but who also promises medicare for all, unbought and unrigged elections, an end to banks and massive corporations utterly taking the piss, and the ability for anyone (because it is their right as an American!!!) who works forty hours a week to support a family without living in poverty.