This chapter highlights the importance of investigating metropolises as distinctive arenas of political conflict. It identifies two key gaps in existing scholarship at the intersection of political science and geography: the predominance of individual-level explanations and the over-reliance on conventional territorial categories, such as “urban–rural” or “region”. Owing to the first gap, spatial patterns linked to the rise of new cultural conflicts and TAN parties have been mostly explained in terms of individuals—who they are and how they interact—while local contexts per se are seldom assigned a significant role. Yet we know from different disciplines that the socio-spatial structures in which individuals are located influence their preferences and actions. Because of the second gap, our understanding of how the intra-metropolitan geography of attitudes and votes has changed (or polarised) after the emergence of the new cultural cleavage remains scant. Building on these considerations, the rest of the chapter expounds on the “metropolitanisation of politics” thesis put forward by Jeffrey Sellers, Daniel Kübler, and others more than a decade ago. Those authors already emphasised how central districts often emerge as cosmopolitan strongholds while suburban areas lean towards ethnonationalist orientations. However, their empirical analyses stopped in the early 2000s. How has the picture they described changed over the 2010s, after the transformations of cleavage politics and the multiple European crises—financial, economic, and refugee? The final part of the chapter reflects on this question, paving the way for the subsequent empirical analyses.