Throughout, as a theorist of democracy, Green has argued that the oligarchic and democratic elements of representative democracy are in constant tension ("American Democracy", ch. 6); that a truly representative and accountable government must have input from participants at all levels of public life ("Retrieving Democracy", 1985); and that representative democracy and modern capitalism—which deepens social inequalities and thus undermines the foundations of political equality—are fundamentally incompatible ("Equality and Democracy", 1999). Pointing out that vibrant democracy must be continuously open to mass protest movements ("American Democracy", ch. 11), he has argued that familiar defenses of social inequality are profoundly ideological and can only be overcome not by philosophy but by collective action ("American Democracy", ch. 4). In addition, he has pointed out that pro-democracy movements are repeatedly undermined by the increasing concentration of mass media ("Primetime Politics", 2005), and the unleashing of gigantic concentrations of wealth, as well as the tendency to institutionalize and contain democracy movements endemic in contemporary American politics ("American Democracy", ch. 9). Finally, he asserts, true democracy is dependent upon a strong state for its protection, rather than the night-watchman state of free-market theorists ("American Democracy", ch. 3).