I just joined a couple of weeks ago and am just blown away by this site. I particularly appreciate Kos' swift response to comments to Leftcandid's diary about why voting for a third party is a mistake. Kos' response can be found here.
Some additional thoughts about the discussion that provoked this response after the orange scroll.
1. Some "protest" voters take the position that they refuse to vote for the lesser of two "evils". I view the second Iraq war as unconstitutional, but I reject the notion that either party is evil. Even though President Obama is probably to the right of my position on the war, and he is a better constitutional scholar than I am, his opposition to the war has forever secured his right to my vote regardless of my other disagreements with him. To call him a lesser or any other kind of evil makes one as bad as a tea party member. Life is always presenting us with less than optimal choices. Make the best available choice and work to give yourself better choices the next time.
2. As for "safe protest votes," in deeply red or blue states, there is no such thing. Human nature being what it is, there are many people that will vote for who they believe will be the winner because they want to be part of the winning team. Therefore, to build the kind of coalition needed to move the country back to the left means the Democrats need every possible vote. Success begets more success.
3. The economy, stupid (James Carville). See Ian Reifowitz's diary here.
4. As President Obama says, we must move forward not back. The longest journey starts with a single step, not 10 steps backward. Do you want to be working to restore Medicare in 2016 or to stop global warming. Without taking what forward steps we can, there can't be any progress to what we all want.