This study conducted a review of the literature on Twitter and politics. The review is summarized under three inter-related themes: 1) does social media help politicians to be elected? 2) who benefits from social media? and 3) political polarization on Twitter. Regarding the first theme, some studies find a strong support for the argument that politicians may create electoral benefits from adopting this new technology, while others fail to find such evidence. Evidence regarding the second query is also mixed. Many have believed that underdogs may benefit the most from social media uses, but several studies challenge this claim by showing that the already established and popular politicians may be those who gain most from their Twitter uses. Taken altogether, previous evidence regarding the first and second queries is mixed. However, previous studies still find strong evidence of increasingly polarizing public opinions on Twitter and of social media’s contribution to this trend.