Now, in going back through histories of the progressive movement, the best source Ive so far been able to find comes through the writings of one Samuel Hays, prolific author and former University of Pittsburgh academic.
You can wade through such of his books as The Response to Industrialism, 1885-1914 looking for trenchant quotes, but I found a better-distilled source in the Hays section of David Kennedys Progressivism, the Critical Issues in which you can find such observations as this one (page 95) wherein he writes that the [progressive] movement for reform in municipal government therefore constituted an attempt by upper-class, advanced professional, and large business groups to take formal political power from the previously-dominant lower- and middle-class elements so that they might advance their own conceptions of desirable public policy.
A century or so later, this same description could easily be applied to Vermonts gentry-left demand for control over everything from nuclear power (minimize it) to public education (maximize it), from capital investment in private-sector housing and commercial growth (minimize it) to personnel investment in advocacy groups, affordable housing, land-use control, and an ever-growing spectrum of environmental initiatives.
Its historically interesting that only a few decades after the initially-somewhat-conservative Progressives articulated this governance by the best and brightest doctrine, it was seized upon by the Russian communist revolutionaries of the 1920s, who wrote and spoke of the Bolshevik Party as the vanguard of the proletariat, that small group that could understand the interests of the proletariat better than the workers themselves, that would seize power in their name, then would help them to achieve their own class consciousness while creating a society that was just and suitable for them, as described by historian Fredreick Kagan of the American Enterprise Institute.
Does this historical retro-glance help explain modern gentry-left political behavior in such states as Washington, Wisconsin, Massachusetts, and, of course, Vermont? You decide.