This conclusion to a special issue on backlash politics develops a proto-theory of backlash politics. The special issue’s introduction defined backlash politics as a particular form of political contestation with a retrograde objective as well as extraordinary goals or tactics that has reached the threshold level of entering mainstream public discourse. While a sub-category of contentious politics, we argue that backlash politics is distinct and should not be understood as ‘regressive contentious politics’. Drawing from the contributions to this special issue, we discuss the causes of backlash politics, yet we argue that the greatest theoretical advances may come from studying backlash dynamics and how these dynamics contribute to different outcomes. We develop a proto-theory of backlash politics that considers causes for the rise of backlash movements, how frequent companions to backlash politics – emotive politics, nostalgia, taboo breaking, and institution reshaping – intensify backlash dynamics and make it more likely that backlash politics generate consequential outcomes.