What we can do, for the moment, is to fix to major superstructural "levels": the one that can be called "civil society," that is the ensemble of organisms commonly called "private," and that of "political society" or "the State." These two levels correspond on the one hand to the function of "hegemony" which the dominant group exercises throughout society and on the other hand to that of "direct domination" or command exercised through the State and "juridical" government. (Selections from Prison Notebooks 12)Now, the novelty and attraction of the concept of "hegemony" (in the second, Gramscian sense) is that dominance within civil society is never entirely secure: there is always space for the articulation of new hegemonic projects, that would disturb and even (eventually) displace the hegemony of those who are currently dominant. This is the famous "war of position." On the one hand, the fact that power is partially secured within civil society (i.e. by means of gaining the consent of those dominated) is the key to the fact that the bourgeois state is resistant to economic or political crisis: "The superstructures of civil society are like the trench-systems of modern warfare" (Gramsci 235). This makes power more powerful. One the other hand, the fact that power has to rely upon civil society (as supplement) is also its weakness. Were the Left able to win the war of position within civil society, then it could take power without even the need for a frontal "war of manoeuvre" against the state (or at least, knowing that the outcome of that war would be a foregone conclusion): victory within civil society would be decisive, in that "in politics the 'war of position,' once won, is decisive definitively" (239).
This is an ambiguity central to the concept of hegemony: it names both power and also certain projects of "counter-power." Hence some have made use of a concept of "counter-hegemony," but this is misleading in as much as it suggests something counter to hegemony per se; counter-hegemony is at best a project for hegemony on the part of some other social group, as Laclau might say in somebody's else's "name." NB this is why (within the theory of hegemony), the political valence of any hegemonic project is crucial. Of course, for Gramsci (and also for the early Laclau), this is determined by the articulation between hegemonic struggle on the one hand, and class struggle on the other. A hegemonic project on the part of the bourgeoisie is clearly opposed to a hegemonic project on the part of the proletariat. Except, that is, in the case of populism. Hence the original problem, for Laclau: how to determine where populism is located on the political spectrum.
As I have said, in Laclau's first approach to the problem of populism, he retains the notion of an articulation between hegemonic struggle and class struggle. From (at least) Hegemony and Socialist Strategy he abandons this idea, terming it "class essentialism." But the problem does not go away, and now that Laclau is returning explicitly to a consideration of populism, so he has to confront it once more.
I am still only just over half-way through Laclau's On Populist Reason. And it is still unclear as to how he may or may not resolve the problem of populism's ambivalence--the fact that there are populisms both of the right and of the left.
In the meantime, however, it would seem that Laclau is threatening to reverse entirely the relation between hegemony and power. Populism is always constituted as a discourse articulated in opposition to some illegitimate power. It is a discourse that appeals to the "common man" against "faceless bureaucrats," "government cronies," "spendthrift politicians," "bourgeois parasites," "the Masonic conspiracy," or the like. Of course, there are important distinctions between these various constructions of the enemy. But Laclau tends to pass over these distinctions. At times he suggests that populism is always opposed to "institutional system" or that it is always "anti-status quo" (123). At other times it is "anti-statist" (91). Sometimes populism confronts "an unresponsive power" (86); sometimes it attacks "the abuse of power by parasitic and speculative groups which have control of political power" (90). In short, however, populism is here defined as a movement of the dispossessed against a source of power. In so far, then, as hegemony is modelled on this view of populism, hegemony is also defined as a project of the powerless.
So, from hegemony as a synonym of power, we are moving towards a concept of hegemony as a synonym of powerlessness.
Now, by any standards this is rather bizarre. Empirically and historically, one might want to point to the numerous examples of populism in power. (Peronism rather comes to mind.) Or one might want to distinguish between different forms of power, either à la Foucault (capillary power) or à la Negri (constituent vs. constituted power). Either way, I am surprised by the extent to which Laclau appears to go along with the populist rhetoric of dispossession.
I think there's much more that could be said here, for instance about the ways in which it is precisely populism (and so hegemony?) that constructs an image of power as emanating from a centre (and so constituted rather than either capillary or constituent). But let us first see what Laclau has to say in the rest of his book. I can't believe that he is unaware of this problem.