The 2020 Green Campaign Could Wither or It Could Thrive
Polling indicates that Bernie Sanders might win the first two Democratic Party primaries (Iowa and New Hampshire). In that case the Dem nomination race might start to look very much like the last one (2016) except it would be Bernie vs. Biden rather than Bernie vs. Clinton.
If Bernie wins the nomination, progressives may not be very responsive to the Green Party presidential campaign. But if progressives get all excited about a possible Bernie nomination and then he again fails to get it (thwarted by the Democratic Party establishment) there might be so much disgust with the Dems that many will throw their support to the Green candidate.
In one case the Green national campaign withers, in the other case the Green national campaign thrives.