Three different presidential elections (2004,2008,2016) I've seen movements built around presidential candidates and then largely disappear. I'm making an assumption about 2016, and 2012 doesn't really count. Obama for America was perhaps the only real movement, but in both 2004 and 2008 the structures were built and then quickly dismantled. Democracy for America has lasted longer than any of the actual presidential campaign movements (yes Dean was a primary candidate, but never a general election one). I'm not sure why this happens when we have to get the band back together every two years, but I suspect it has something to do with the general lack of comfort with building and sustaining a membership movement over which the members have some input, rather than a top down organization built around a personality.
My least favorite savvy thing these days is "demcocrats don't vote in the midterms!!!" Well I wish they did, more, but the real point is "why don't highly paid professionals with million of dollars in campaign money know how to get people to vote???" Maybe they're doing it wrong?