As I continue to work my way through Agamben's Homo Sacer: Sovereign Power and Bare Life I'm begining to understand that the figure of homo sacer can be seen as an ongoing project for Agamben. This paragraph from this background text on Wikpedia captures the dimensions of the project well:
"Since its origins, Agamben notes, law has had the power of defining what "pure life" is by making this exclusive operation, while at the same time gaining power over it by making it the subject of political control. The power of law to actively separate "political" beings (citizens) from "pure life" (bodies) has carried on from antiquity to modernity - from, literally, Aristotle to Auschwitz. In a daring but plausible move Agamben connects Greek political philosophy to the concentration camps of 20th century fascism, and even further, to detainment camps in the likes of Guantanamo Bay or Bari/Italy, where asylum seekers have been imprisoned in football stadiums. In these kinds of camps, entire zones of exception are being formed. Sovereign law makes it possible to create entire areas in which the application of the law itself is held suspended."
Agamben states it thus:
"I am not an historian. I work with paradigms. A paradigm is something like an example, an exemplar, a historically singular phenomenon. As it was with the panopticon for Foucault, so is the Homo Sacer or the Muselmann or the state of exception for me. And then I use this paradigm to construct a large group of phenomena and in order to understand an historical structure, again analogous with Foucault, who developed his "panopticism" from the panopticon. But this kind of analysis should not be confused with a sociological investigation."