We demonstrate the importance of politician social networks for electoral outcomes. Using large-scale data on family networks from over 20 million individuals in 15,000 villages in the Philippines, we show that candidates for public office are disproportionately drawn from more central families and family network centrality contributes to higher vote shares during the elections. Consistent with our theory of political intermediation, we present evidence that family network centrality facilitates relationships of political exchange. Moreover, we show that family networks exercise an effect independent of wealth, historical elite status, or previous electoral success.