A better idea is to do to the Democratic Party what the Tea Party and MAGA did to the Republicans.
Primary out corporate candidates and push for progressive ones at every level. President, congressional rep, school board trustee, dog-catcher: it doesn't matter.
The problem progressive voters have is that they don't show up, and the especially don't show up during off years, in primaries and in down-ballot races. The polticial right, by comparison, has been getting people in place on small races for years.
Sanders did more for progressivism by enthusing Democratic members to vote in primaries and down-ballot races than Stein or any third party has ever done, and we're seeing results. It needs to continue.
Set phasers to burrrrrrrrn.