To understand Pedro Sánchez's victory in the contest for the leadership of the Spanish Socialist Workers' Party (PSOE) on Sunday night, we must first accept the existence of two external (but not far removed) driving forces that were mostly beyond the PSOE's control. Firstly, the economic crisis of 2008 and the [collapse of traditional social democracy][economist] as a viable governing alternative across Western Europe; secondly, the rise of alternative left-wing parties or currents (Syriza, Podemos, Corbyn, etc.) in response to that first phenomenon. The economic environment within which s...