Dayen argues that the public option fight "fundamentally transformed the tactics and strategies of whatever is left of a progressive movement." He continues:
[T]he trust of the base to use the normal mechanisms of politics to advance goals simply crumbled. That’s why you’re seeing a dearth of promises from candidates about the public option. Base voters have become increasingly cynical that those promises mean anything. So why bother making the promise in the first place? The progressive movement is undergoing a transformation where they no longer see engagement with candidates as the best or only strategy to advance goals. Those not hopelessly alienated by the entire political process prefer outsider strategies that force political pressure from the bottom up, rather than relying on the promises of those politicians to carry the day. That’s the new reality...Is Dayen right about what "the progressive movement" believes? I don't know. It's easy to forget that most liberals supported ACA and support Barack Obama, but I'm not aware of any solid evidence about what activists believe or how they're acting. I'm sure he's correct about some, but I have no idea how significant that is in practice.
If he's right, however, than that's too bad for liberals, and it's a fundamental misreading of the 2009-2010 ACA battle. After all, the truth back then was that Democratic candidates in 2008, and certainly Barack Obama, placed very little emphasis on the public option as a key campaign promise. It was certainly mentioned, but it was presented as a minor component during the campaign. So in view, it's a major misreading of the ACA fight to read it as showing that liberal politicians can't be trusted to keep their promises. Instead, what ACA showed that promises matter a lot, but that there's a lot of complexity involved -- higher profile promises matter more than those on which the candidate places less emphasis, and sometimes it's Members of Congress who matter as much or more than the president.
That doesn't mean, by the way, that political action outside of basic electoral politics is pointless. My general guess is that people gravitate and should gravitate to where they're most comfortable. But in purely instrumental terms, one of the best investments that I can think of in politics is in getting politicians who want to be seen as sympathetic to your point of view to actually support the issues you care most about.
My prediction had been that activists would make it clear to liberal candidates that the public option was now a high priority, which would translate into quick action whenever the next chance happens for fulfilling the liberal agenda (just as family leave passed quickly in 1993 and the Lilly Ledbetter Act passed quickly in 2009. For liberals to react to ACA passage instead as fundamentally a betrayal would be a mistake; for them to react by giving up on forcing politicians to make future promises would basically be an excellent way for liberals to lose all influence in Washington.