Who says anyone ever have to vote for anyone, Green, Dem or whatever, unless it serves their interests in that election? Politicians work for the voters-- it's not some kind of romantic relationship. They have to earn the vote every time and if running a Green in a safe Dem district will force them to heel, I have no problem with that-- although I usually think running in the primary is more effective tactically.
But if your concern is boosting the Green vote, it is exactly this "vote Green no matter what" attitude that is making a lot of progressive Dems vote against Greens no matter what, for fear that any uptick in their vote will encourage more challenges to folks like Wellstone and other progressive Dems. I used to support tactical voting for Greens-- hell I voted Green against Feinstein, was appointed to a labor commission by a Green city council person, campaigned for a Green running for Oakland city council-- but the absolute lack of tactical sense by many Greens has made me hope they get smashed even in races where it doesn't matter, for fear they'll use credibility to run in elections where they can throw it to a GOPer.
I'd love to have a third party out there that was available to tactically punish rightwing Dems and run in safe Dem districts, but the Greens have instead chosen to seek notoriety in exactly the races most likely to toss the elections to the GOP. It makes sense from a publicity sense-- running against Wellstone got national publicity -- but it goes against what folks used to tell me was the original Green strategy, namely running in local races and creating a cadre of credible candidates at lower levels. Instead, you have lots of energy on Presidential and state level races, and almost zero successes at local legislative levels.
-- Nathan Newman