We develop an equilibrium theory of attention and politics. In a spatial model of electoral competition where candidates have varying policy preferences, we examine what kinds of political behaviors capture voters' limited attention and how this concern affects the overall political outcomes. Following the seminal works of Downs (1957) and Sims (1998), we assume that voters are rationally inattentive and can process information about the policies at a cost proportional to entropy reduction. The main finding is an equilibrium phenomenon called attention- and media-driven extremism, namely as we increase the attention cost or garble the news technology, a truncated set of the equilibria captures voters' attention through enlarging the policy differentials between the varying types of the candidates. We supplement our analysis with historical accounts, and discuss its relevance in the new era featured with greater media choices and distractions, as well as the rise of partisan media and fake news.