Someone should do an epic rap battle on Roslyn Fuller's essay, Democracy — Too Much of a Good Thing?, a pointed rebuttal of Andrew Sullivan's Democracies End When They Are Too Democratic. Fuller argues that Sullivan's application of Plato's polemic against democracy (from The Republic) is inapt.
Fuller notes that the American republic is modeled not after the Athenian democracy of Plato's time but explicitly and intentionally after the Roman republic. Thus, whatever the reasons for our conflict, they cannot be about too much democracy, because we don't have any democracy. Instead, surprisingly enough, our problems closely resemble the problems of the Roman republic around the time of Julius Caesar. In Caesar's time, the republic was not democratic, but had some public participation in elections. The elites became out of touch with the common people, and Caesar was charming enough to harness their dissatisfaction to use the elections to gain control of the Roman state, and his heir was able to overthrow the republic. (Note that the Roman Empire lasted undivided for more than 400 years, and the eastern empire lasted another millennium; the fall of the republic does not necessarily entail collapse.)
In contrast to Fuller's direct and compelling comparison, Sullivan's analysis is vague and theoretical. Indeed, in his defense of his original analysis (appended to Fuller's essay), Sullivan explicitly disclaims attempting any historical analysis whatsoever. Sullivan further specifies that what he means by democracy is the "the very recent democratization of online media." But online media, however open to the public, is not democracy: it is not state power held directly by the people. If online media is Sullivan's "hyper-democracy", then it is difficult to see Sullivan's argument as anything but that the people should not even have an independent voice not carefully crafted by the neoliberal ruling class.
It is also important to consider Plato's criticism of democracy in its context: Plato argues that even his ideal republic (which is a "republic" only in the loosest sense that it is without an actual monarch) will eventually become corrupted, leading to a process of degeneration and renewal, in which democracy is but a single step along the way. Even if Plato were correct (and I don't think he is), using Plato to condemn democratization is like using Newton to condemn gravitational acceleration: yes, if you are falling, gravitational acceleration will have very bad consequences, but Plato claims that the process of political corruption is just as inevitable.
We must keep in mind that Andrew Sullivan is a neoliberal, and if successful, the neoliberal project must necessarily end in the absolute disempowerment of the people. Any actual power must be stripped from the people — they will simply use it unwisely — and the people must be left with only the illusion of power. Even the kind of individual power the various capitalist ruling classes thought would perpetuate their rule — the power of whites over blacks, natives over immigrants, men over women, parents over children, law-abiders over law-breakers — just fuels fascism, which the neoliberals fear almost as much as they do democracy and socialism. Any "democracy", any actual power held by the people, is too much democracy.