In Which Mayor Mugwump Examines Prendergast's Downward Spiral

Holmes is interesting and all that, but he's... Morbidly interesting. Fascinating in a grotesque sort of way. Whereas Prendergast... Well, his descent into madness was far more entertaining, as it happens over a long stretch of time in perspective to the audience.

When we started seeing little tidbits about Prendergast, he seemed completely unrelated to the two main plots, but I knew that he would become important, seeing as attention was drawn to him specifically. I particularly enjoyed how the passages featuring him became slowly more unsettling, and portray his deteriorating state of mind.

What I'm wondering is... At this point, were his assumptions unfounded? Was the corrupt spoils system still really around at all, or was Prendergast living in the past? Also, did Prendergast actually do any kind of successful campaigning, or was he absolutely completely delusional from the beginning?

Because, as interesting as Prendergast's snap was, I'm unclear as to how much was because of actual real feelings of betrayal and how much was the problem of him being absolutely bonkers.