The realm of politics, as has been observed, has much in common with making sausage. It’s messy, even bloody, seldom includes premium ingredients. And there’s butchery at points.
Look, if Donald Trump wins the White House, everything Jill Stein stands for in a Green Revolution’s toast. It doesn’t take long to destroy the hard-gained agencies we have, much less to strip-mine hillsides and rip up forests. That’s why a vote for Stein is a vote against a Green agenda — it’s blatantly a vote against Hillary Clinton. If you think there’s no difference in the major parties on this issue, you’re deluding yourself. Or listen to what Trump thinks about real women like Clinton and Stein.
There’s a huge gap, too, between articulating policy and implementing it, as well as moving from the ivy tower into nitty-gritty management overseeing a host of federal agencies. You want to get anything done, you’re going to get dirty. It’s the nature of working with others. It’s the reality of winning battles, too.
Radical movements have a history of fragmenting, as Christopher Hill notes looking at the waves of ferment during the English civil wars and Protectorate.
Let’s not do it again. Rally around Hillary Clinton and regroup later, on the high ground.
Jnana's Red Barn 
You nailed it. A vote for either if the spoilers is a vote for Trump.