The proof would be in the puddin', and if Americans didn't like the policy they got, they could vote the bums out. In the past century and a half, political theorists like Mosca, Pareto and Schumpeter wrote lengthy treatises that argued that elites would inevitably rule. So elites have always ruled. Thus, in some measure the question boils down to which elites shall rule. Judis, in grad student fashion, hands out hats of two colors.
Black hats go to businessmen and capitalists, white hats to union leaders and social liberals.
Judis does not explain this, though clearly it is not by way of the ballot box. This is hokum. Of course not. But to make this argument one has to close one's eyes to the historical record. Happy though the Progressive days were, Judis laments that they may be gone forever.