The mention in the footnote does not serve to balance the text in the main body to the effect that "Gilens and Page do not characterize the US as an "oligarchy" per se."
Furthermore, the concept of "civil-oligarchy" is easily important enough to require introduction in the main body. Thus, using the block quote with the prefacing sentence as I have done serves to both introduce the concept and accurately represent the gist of Gilens and Page. That is a balanced text. 連絡 見学/迷惑