readers, help: is it who or whom?

Elsewhere, the editor of Skeptic magazine—[who(m)?] you might expect to be a tough sell—called Born to Rebel ”the most rigorously scientific work of history ever written” (Shermer 1996, p. 63)

(Yes, this means I am up in my office writing late on a Saturday night. I've never had much pretense to a life. I guess I will admit to feeling a little pathetic--not, though, because of being up at the office working, but because I'm listening to INXS while I'm here.)