This post from Matt Yglesias drives home one of the most important points currently facing the progressive movement. The Big Tent results in a fractious chorus of interests competing for attention and address. We simply don't have the monolithic certainty of the still-powerful Christian Right.
Part of the problem stems from the nature of the secular progressive mindset. With a worldview derived from the notion of applying logic and reason to our environment in order to better understand it, we derive an awareness of just how little we truly know. For example, I'll freely admit that I know very little about the manufacture of pogo sticks. Consequently (and reasonably), if there were a progressive movement agitating for a reform in the way pogo sticks are made, I would leave advocacy on that topic to those who (presumably) are the experts. I might cheer them on based on their progressive bent, but I'd be unlikely to stake any serious effort on their behalf without taking the time to get a decent handle on the topic -- and with the ever-multiplying array of issues facing the nation, best of luck to anyone who seeks to get a decent handle on every topic ahead of us.
Now contrast that with the Right. Yglesias highlights a case of Christian advocacy groups working to prevent a restoration of pre-Bush tax levels on the wealthy by making it a "family values" issue. Absurd? Sure. But this is just one example among many of the modern conservative movement aligning with other conservative issues for a cohesive stance -- and more importantly, cohesive application of political pressure.
I certainly don't advocate a progressive monolith in response; our intellectual integrity requires us to respect the limits of our own knowledge and ability. What I do suggest, however, is an application of one of the tools of the skeptical movement. Given the broad, deep, and ever-expanding state of science, it is simply impossible for any person to know everything about anything, let alone everything about everything. When confronted by a new piece of information, rational people ought to examine it for plausibility based on their current knowledge; but they ought also to consider the source, recognizing that peer-reviewed experts do have additional credibility (though by no means infallibility).
I suggest a similar process here. Consider the advocacy issue, consider the source, trust the experts -- and lend a hand. We progressives are on the same team; where the Right instills team spirit by generating monolithic conformity and conflating each other's issues, something we neither can nor should do, we can approach a similar team ethos by deferring to the experts in each field and accepting their call to action to apply political pressure on their behalf. Understand that every progressive victory begets more progressive victories. The conservatives certainly understand this, which is why they oppose every single vote on every single topic. And when your important issue needs a boost, you know who to ask -- your teammates.
We're the left. Solidarity is in our blood.
Use it.