I'm an independent that leans left too. I voted for Obama in 2008 and don't regret it. He did a great job selling a vision that didn't work out in the end. What did work out was his centrist treadmill policies that do nothing but continue the neoconservative status quo. So yeah, live and learn.
The problem is, it would take the entire nation going back in time and changing their vote for it to make a difference.
I voted for Ron Paul, and I still would. I'm voting for Gary Johnson this year. I suggest you look at his policy proposals and decide for yourself. You won't be throwing away your vote, you'll be advancing a political movement that has long been needed. This thread proves two things to me. That the left insist on trying things that are doomed to fail, and when they do fail, they say they didn't spend enough or do whatever it was in a big enough way. The right had its chance, for the first time in over 50 years, to govern and their chief accomplishments were years of nation building overseas, deficit spending, and ridiculous positions on social matters from immigration to civil (gay) rights). The stupid thing we voters do, IMO, is to keep electing one or the other expecting better results somehow.
I think a vote for Gary Johnson is a vote for Obama, or against Romney. All it does is hurt the republican candidate. That being said, I think Gary Johnson would make the best President