What is fascism today, in our social media world? How does Donald Trump's political persona feed tendencies toward it? What new concepts do we need to grapple with its unique contemporary incarnations? This book takes Trump as a jumping off point to rethink fascism and its preparatory tendencies. Existing theories revolve around the identification of the "masses" to a charismatic leader, opposing the mass's "delusions" to business-as-usual "rational" politics. However, in today's micro-segmented social media environment, the "masses" no longer exist, and politics is any but business as usual. Far from being duped into movements fueling fascism, people positively desire them. They exuberantly participate in an affective regime that is not the opposite of rationality, but constitutes its own anomalous form of it, and even fosters a certain intellectuality expressed in the exegeses of conspiracy thinking. "Reaction" sums up this affective regime in a single word. This book is a political treatise on the cultural conditions of fascism, combined with a philosophical treatise on becoming reactionary as a collective process. The philosophical inquiry requires reconsidering the very concept of the person, and inquiring into what collective personhood might mean. This can only be done by advancing nothing less than an alternative political logic.