On August 10, I wrote about a long-standing theory of mine, that the Democrats' culture of caution has been the single biggest reason for Democratic failures, both electorally and policy-wise, over the last 20 years. I think the Bush Dogs campaign we've begun here at OpenLeft.com is a great example of one way to begin to break down that culture. Today, I want to examine the two big long-term structural barriers that keep the culture of caution alive and well, and to lay out some ideas as to how the three pillars of progressive politics can work together more effectively to overcome these barriers.