The image it evokes applied to "campaign" is dysfunctionality rather than castration, emasculation, impotence. That an erect penis is snapped, broken, references structural disorder, I would say. Seems to be borne out by the context, too (see #1 and the page in the book, #2).
"broke" of course can also simply mean "not working" (#6).
New to me:
In the military culture, a popular term for a person who is weak or has an injury that hinders the ability to perform services is called a “broke dick” (Felsman, 2014). Words can have a powerful effect over how one perceives a situation. This notion of weakness or “broke dick” seems especially poignant, as someone may ...
(E. C. Ritchie, ed., Intimacy Post-injury: Combat Trauma and Sexual Health, 2017)