If you circle in the ballot for Gillum on the Working Families Party line instead of the Democratic line he's still a democrat Gregor. He doesn't change who he is or what he's running on. It merely means that WFP was able to deliver X amount of votes to the democratic candidate. If it's a significant number Gillum will have to keep their interest in mind.
Or you can vote on the straight right wing Goldman Sachs ticket and see how well that works out.
Oh wait we already have.

I'm not interested in Scandanavia or apocalyptic comparisons PIA. I'm merely interested in advancing progressive causes. Applying pressure where ever possible.

Crickets for the question of how straight party line voting advances progressive causes?
Ya can't even get a minimum pay raise passed from that set.