… is from page 273 of Stephen Holmes’s insightful 1990 essay “The Secret History of Self-Interest,” which is chapter 17 in Jane J. Mansbridge’s 1990 edited collection, Beyond Self-Interest (footnote omitted):
Another politically important form of affection is identification with a leader. This is what [David] Hume calls “imaginary interest,” whereby individuals attach themselves psychologically to a leader whom they will never meet and from whom they can expect no material benefits. Quasi-erotic fixation on prominent individuals may sometimes inspire acts of personal foolhardiness or courage. But it usually has less dramatic effects. For instance, it allows devotees to live national events vicariously, to feel involved in large affairs.