One certainly hopes so.
But if we do get some catchily strident far-left candidate who collects a significant following then loses the D primary, I do expect a lot of them to be sour grapes stay-at-homes in Nov. Just like there always is. Sort of a replay of Bernie vs Hillary.
They’ll justify it to themselves by something along the lines of: “Only the hard left can counter the hard right. Wishy washy conventional centrist Democrats won’t do a thing to stop the Fascists, so we’ve already lost.”
Note how many smart hip people here have argued loud and long for years that abstaining from voting for your team does not amount to a vote for the other team. Of course it does, but they’re not able (willing?) to comprehend that.