That is highlighted not only by his central role in enabling every War on Terror excess, but also by this fact:

Hastert's ability to make such large cash payments probably came from his career as a K Street lobbyist. He entered Congress in 1987 with a net worth of no more than $270,000 and then exited worth somewhere between $4 million and $17 million, according to congressional disclosure documents.

That common arc is more of an indictment of U.S. political culture than Hastert himself, but he's certainly been happily and hungrily feeding at the trough. A political system that essentially ensures that every powerful political official becomes extremely rich is one that is inherently corrupt — as we've been taught for decades about those Bad Other Countries — and that is the most interesting and most important part of this story.