The argument of this paper is that the emergence of military dictatorships, such as the Brazilian regime of 1964, is not caused by an economic crisis of dependent capitalist development. Rather, it results from a polarization and radicalization of the democratic regime by which it is preceded. Democracies handed down from above, like that in Brazil and other South American democracies, lend themselves to polarization and radicalization. They therefore favor the emergence of modern forms of autocracy.