This book evaluates the transformational process of left populism across grassroots, national and European levels and asks what we can do to harness the power of broad-based, popular left politics. While the right is using populist rhetoric to great effect, the left's attempts have been much less successful. Syriza in Greece and Jeremy Corbyn's Labour Party in Britain have both failed to introduce socialism in their countries, while Podemos has had better fortune in Spain and is now in government with the Spanish Socialist Workers' Party. Bringing a wealth of experience in political organising, Marina Prentoulis argues that left populism is a political logic that brings together isolated demands against a common enemy. She looks at how egalitarian pluralism could transform economic and political institutions in a radical, democratic direction. But each party does this differently, and the key to understanding where to go from here lies in a serious analysis of the roots of each movement's base, the forms of party organisation, and the particular national contexts. This book is a clear and holistic approach to left populism that will inform anyone wanting to understand and move forward positively in a bleak time for the left in Europe.