When you try and sum up the key moments of election year in the US, it's likely that at least one of your memories will have been influenced or even inspired by a social media meme. That's because, as this Politico article points out "This was the first presidential cycle in which the full complement of social media tools were mature enough to alter the canvas of American elections in ways that may not have seemed to matter at the time."
So did they matter? Politico makes a good case that the "Texts from Hillary" meme succeeded where teams of spin doctors failed and gave Hillary Clinton the hip, youthful makeover necessary to make her a serious contender come 2016. In retrospect, it's also very hard to argue that the leaked "47 per cent" video didn't have a very damaging impact on Mitt Romney's campaign - although it needed the traditional media to bring it out of obscurity and onto the agenda.