I appreciate the perspective brought by Conceptual Guerilla here. Read it, if you haven't.
His argument, as I see it, is "look, if candidates run on and push hard for the liberal agenda that many of you want, they will, at least some of the time, lose badly - look at Alan Grayson."
While I agree that some candidates will lose with a more liberal agenda, I think others will win more votes by demonstrating a stronger and more sincere commitment to progressive values.
For example, I'm proud to have Sherrod Brown as one of my senators in Ohio. I had the opportunity to meet him while working for Jennifer Brunner's SoS campaign in 2006. You could pick friendlier areas to run than Ohio
I feel like Sherrod is a good example of a candidate running on a relatively progressive agenda, making people believe they will really be a progressive, and then winning.
There is also a difference between being savvy at how you run, and what values/agenda/etc you decide to run on. In other words, running as a fire-breathing, in-your-face, unapologetic liberal might be fun, but it can alienate people. I think that may have had something to do w/ Grayson's loss, while Guerilla's point is well-taken.
Regarding the president, my perspective is this: I expect the president to work up to his capabilities to implement the agenda he has promised. If I felt like he wasn't very capable, I would probably be very happy with the results we have gotten. But I think he is extremely capable when he wants to really put everything he possibly can into an issue. Maybe it's the "cool approach" which he had at various points, and letting congress take the lead on issues. I thought there was a lot of merit to that during the healthcare stuff. But I couldn't help but feel after the debt negotiation that he has made his role (or at least given me the impression) much less important and substantial. Perhaps that impression isn't merited, but that's how it feels. He feels more irrelevant now than he did at the beginning of his term.