It's the same problem the social progressives (read: religious right) have been facing (and will increasingly face) with the Republicans. The short answer is "No, if you want to avoid handing control to the Republicans, who are infinitely worse." I think the best thing to do is brand yourself within the party and nibble away from the bottom up. The Tea Party did this to great effect, and shifted the Republican party even further to the right by knocking down more regional House slots. They still ran as Republicans but they were branded Republicans and the brand meant something. It's worth keeping in mind that while the Tea Party succeeded in moving the Republicans to the right and not splintering the vote in the Dem's favor by going 3rd party in head to head races, their strategy still cost the Republicans dearly in some races. They are still grappling with the pros and cons of the swollen Tea Party ranks. But it was the most effective branded ideological shift I've seen executed in my memory. They had a lot of billionaire and media help though. They weren't as grass roots as they claimed to be. Edit: I once heard a Green Party candidate running for a local seat speak. I shit you not he worked himself into a frenzy and at one point started yelling "And we will rise up with our Green brothers and sisters in Germany and...." I mean, he lost me before that, but I was half expecting a Heil Hitler. I've seen many Greens reference Germany and it makes me infer that there must be a really strong Green party presence there. Makes me not even go near considering a domestic Green candidate. It's bad enough they are making a platform out of a single issue without forgetting who they are representing.
All the chatter that makes its way to me via listening to them or reading online seems to be pretty much about the environment. Admittedly, they could be a lot more diverse issue-wise (I haven't gone out of my way to investigate them), it's just that the stuff they present at a glance has always been one issue. The fact they started in Germany makes complete sense in context of what I've gleaned hearing from them so far. Thanks.
Democrats = Republicans on most issues: Protracted wars? Good for our donors. Not prosecuting financial industry crimes? Good for our donors. Subsidize oil? Good for our donors. They agree to differ on abortion and gay marriage, take turns holding power, and laugh all the way to the bank. So yes, they should ditch the dems.
The topic for this thread is misleading. The linked article is about a different topic, and its author is already outside the Democratic Party. The article is about tar sands and the Keystone XL pipeline. The author of the article is the media co-ordinator for the Green Party. He's making a sales pitch for his party. Fracturing the Democrats is incidental to his goal. Oh, and I liked what ecib said.
I don't consider the title to be misleading. The article does speak at length about the Tarsands and Keystone XL, but it's only used as a wedge issue to deface the Democrats. Other issues are discussed as well. Obviously any article answering the question "Should progressives ditch the Democrats?" is going to discuss fracturing the Democrat party. I considered the Green party affiliation of the author when I added the #greenparty tag.
I think with election reform, you can hope Republicans move towards the middle. This would move Democrats in left position on Social Liberal position and on Liberalism foreign policy. If for election reform causes republicans to lose most important elections Democrats will become a super party. In that case progressive wing would then fight more Conservative members of their own party. If their were any thing close to Progressive/Labour/Socialist party outside of the Democrats, their would need to be Round Voting system where the winning candidate would have to get 51% at least to win.