Yuval Levin offers an excellent two-paragraph summary of the evolutionary history of our current political bifurcation in “What Is Constitutional Conservatism?,” which appeared in the November 28, 2011, issue of National Review:

One view, which has always been the less common one, holds that liberal institutions were the product of countless generations of political and cultural evolution in the West, which by the time of the Enlightenment, and especially in Britain, had begun to arrive at political forms that pointed toward some timeless principles in which our common life must be grounded, that accounted for the complexities of society, and that allowed for a workable balance between freedom and effective government given the constraints of human nature. Liberalism, in this view, involves the preservation and gradual improvement of those forms because they allow us both to grasp the proper principles of politics and to govern ourselves well.

The other, and more common, view argues that liberal institutions were the result of a discovery of new political principles in the Enlightenment — principles that pointed toward new ideals and institutions, and toward an ideal society. Liberalism, in this view, is the pursuit of that ideal society. Thus one view understands liberalism as an accomplishment to be preserved and enhanced, while another sees it as a discovery that points beyond the existing arrangements of society. One holds that the prudent forms of liberal institutions are what matter most, while the other holds that the utopian goals of liberal politics are paramount. One is conservative while the other is progressive.

Where Levin begins to go wrong — or, more precisely, trails off prematurely in his analysis — is in assuming that both forms of liberals (or “conservatives” and “liberals” in modern American parlance) can still have somewhat related goals despite their different perspectives.  Put differently, if our current state of coinciding prosperity and freedom is “an accomplishment,” then the objective of political action is to manage power so as not to undermine the achievement; if it is “a discovery,” implying an inability to undiscover it, then the objective becomes to marshal power for more expeditious achievement of progress.  The latter is certainly utopian, but it does not consider itself to be such.

This distinction is clear as day in Levin’s introductory description of an apparent paradox in current liberal politics: populism versus technocracy.  He illustrates the latter as follows:

In September, Peter Orszag, President Obama’s former budget director, wrote an essay in The New Republic arguing that “we need less democracy.” To address our country’s daunting problems, Orszag suggested, we need to take some power away from Congress and give it to “automatic policies and depoliticized commissions” that will be shielded from public pressure. “Radical as it sounds, we need to counter the gridlock of our political institutions by making them a bit less democratic.” Two weeks later, North Carolina’s Democratic governor, Beverly Perdue, made a less sophisticated stab at the same general point, proposing to suspend congressional elections for a few years so members of Congress could make the difficult decisions necessary to get our country out of its deep problems.

What comes immediately to the conservative mind is page 9 of the cartoon Road to Serfdom:

In short, the central planners prove unable to make things work functionally, so the society looks to suspend the difficult deliberation of democracy and its inherent battle of self-interests.  Populism fits into the mix as the underlying power base of the budding dictatorship.  This strain of thought was clearly audible in President Obama’s public declaration bank CEOs that his “administration is the only thing between you and the pitchforks.”  It is, in other words, the populist zeitgeist (often manifesting as nationalism, but class warfare works, too) is the cudgel that the reigning technocrats use against educated, influential groups that have a differing vision.