Electoral prediction and social media met in 2010. The reasoning was straightforward: people use social media to express their opinions and, therefore, it should be possible to use that information to capture the mood of the public and even predict electoral results. However, in spite of many attempts, the subfield has still not produced a commonly accepted, generally valid method. In this Chapter, we discuss the original foundations of the field, and the limitations that still pervade it. We outline some of the reasons why this program has generally remained stuck in the same original challenges that were identified ten years ago.