This article considers the phenomenon of MAGAism as a general, “big-umbrella” social movement to probe its structure and persistence. Drawing on my research on nationalist movements, I discuss the narrative flexibility and emotional power of nationalism and consider how these characteristics fuel a particularly resentful form of majoritarian nationalism—MAGAism. I identify five points of entry for MAGA participation, starting with this bitter majoritarian nationalism, then populism, then traditional conservatism, next a Trumpian personality cult, and ending with the alt-right’s extreme white supremacism and fascism. I then discuss two forces that gather this unlikely collection of groups and individuals under the MAGA umbrella: (1) the flexibility of social identity and how it allows status-threat narratives to subsume and redirect economic and political claims; (2) the social media environment of the 2020s, cut loose from the traditional gatekeepers of news and information, wherein maximizing hits—not accuracy—is the guiding principle. On the one hand, social media intensify the prominence of the demagogic celebrity at the helm of the Republican Party, Donald J. Trump. On the other hand, alt-right trolls compete for prominence by seeking outrageousness and shock value, enhanced by algorithms that create a closed information environment. These social media trends pull MAGA adherents further to the right by inflaming public discourse and building the movement on lies and conspiracies.