This book studies the challenges to conventional politics posed by new ways of selecting candidates for legislative elections. The recent economic crisis had profound political consequences on politics, generating an upsurge in the demand for more participative ways of decision-making in politics channelled through social movements and individuals in different countries. Some parties have reacted by introducing changes in their internal organization (via intra-party democracy), particularly related to the selection of candidates for public office. This volume explores the trends and challenges of these new methods of selection, analyses how the internet is increasingly being used as a selection tool, and evaluates some of the relevant consequences related to political representation, party cohesion and party centralization, among others.