Bombadil.... you'll have to find a libertarian for that position! I like the metaphor of Hillary as a giant spider, that's why I suggested Ungoliant or Shelob.
Any nine Democrats can be the Nazgul.
Carvile has got to be the orc (regular type). I think Dashole or Gephart would be best as Sauruman, the soft spoken totally evil personna. McCain acts like Denethor, proud, arrogant and totally wrong in the end. Barbara Bush as Galadriel. Does that make Bush the elder Celeborn.
As an aside, are those wild men posted two or three hundred back from the battle of Helms Deep? If so that would make them the Dunlanders that sided with Sauruman.