I just got The Sound on the Page, by Ben Yagoda. I haven't read it yet, but I did peek ahead to the section on persuasive writing. I found a piece by Justice Stephen Breyer, saying why he puts citations in text, not in footnotes:
I believe most footnotes are distracting. The purpose of a citation in a court argument is not to prove what your source was but to add to the argument. If it doesn't add to the argument, don't put it in. So I place citations in the text. If I removed all citations from the text and put them in footnotes, the article or opinion might read better because the flow of the argument wouldn't be interrupted, and one's eyes wouldn't be distracted. I don't do that, because I want to use the cited case as part of the statement I am making.
(I'm sure that Mike will be pleased.)