A call for understanding a new phenomenon

Populism is not yet properly understood and definitions of it are still highly controversial, especially since it is a label that is applied to a wide range of political movements that have very little in common. It is also highly controversial whether populism should be classified as an ideology, a political style, or a socio-political mentality (For a review of the state of the art on the different definitions of the populist phenomenon, see:  \citealt{urbinati2014,Tarchi_2016}). It is a complex and variegated galaxy, better identifiable for the problems it mentions than for the solutions it proposes. We will need to distinguish between various forms based on their left/right/anti-systemic ideologies, their effects on consolidated democracies/young democracies/countries in the transition to democracy, and their national characteristics, especially the Europe/United States divide