Rather than focusing on the issue of the ‘crisis of representative democracy’, this book proposes to take an interest in ‘political innovations’ that are carried out by a wide variety of actors (elected officials, political parties, citizens, stakeholders, interest groups). What changes do these political innovations introduce? If so, how do they manage to renew the way representative institutions work? To answer these questions, we propose not to limit ourselves to the study of ‘democratic innovations’ (particularly deliberative innovations) but to deal with the concept of ‘political innovations’ in depth. We argue that one could observe different ‘innovation streams’ that affect representative institutions at the same time: ‘elite selection’, ‘governance’ and ‘technological’ streams. We highlight two central ideas in this introduction. Firstly, understanding the evolution of representative democracy requires preserving the way it usually functions without limiting it exclusively to ‘innovations’ (party system, public participation, new technologies). Secondly, no political innovation is inherently ‘democratic’: its effects on the democratic ‘quality’ of regimes depends on its interweaving with other ‘streams’ at work and remain dependent on the political uses it is subject to, both on the side of those who conceive it and those for whom it is conceived.