The story is about the town bully who is allowed to run wild until the town is basically forced to take action into their own hands. After years of his stealing, abusing and threatening violence to anyone who crossed him (or who he imagined crossed him), they finally gun him down in the middle of main street. The author takes great pains to argue that the final killing was not something planned. At that point, the town had just come together to defend themselves after the nth time that the authorities had failed to prevent him from fucking with them. It was supposed to just be a patrol to keep a constant watch on him and to protect the family of the people who were going to testify against him (up until then, he had intimidated and isolated all witnesses for previous crimes) but somehow they just snapped and started firing.
It's a fascinating book to read post-Trump. This is definitely flyover country and probably voted for Trump. In Broad Daylight never specifically addresses politics. The book, like the town itself would like to think, is apolitical. But the undercurrents of the belief in minimal government turning into activist aggression against any government are very present. Here you see both the independent, individualistic culture of farmers and their workers and the angry blame-everybody else resentment of that same culture when it is uncoupled from basic moral values. MacLean only treats the how and why of that uncoupling indirectly, basically telling McElroy's life story and the story of the town in as factual terms. There are reasons for McElroy to have been such a complete psycho. He is of the tenant farmer class, who live in poverty, dependent on the indirect work needed to support agriculture, both legit and criminal. He does seem to be geniunely psychologically disturbed, perhaps from an earlier farm injury. He also hates all the farmers, partly as the undeserved scapegoats of his own narcissistic personality, but also because of how he was treated in school and in society as basically white trash.
You really do feel for the townspeople. MacLean does a good job of explaining how they allowed McElroy to go as far as he did. The system definitely failed them time and time again. McElroy had a scumbag lawyer who played the rules to the hilt for the advantage of his clients, without any moral concerns whatsoever. The rules themselves which were designed to protect individuals from the state, also can be bent to protect truly bad individuals at the cost of the community. And finally, the town itself lacked real community cohesion, both due to its individualistic history and its long-term economic deterioration, which drove out young people. Finally, when they do take him down, the backlash is both a media onslaught with a lot of after-the-fact moralistic hand-wringing about vigilantism and a sudden involvement of multiple levels of law enforcement right up to the FBI, none of whom could do shit to stop McElroy from running wild beforehand. McElroy's tactics are very similar to Trump's actually, and the system failed almost up to the breaking point. The depressing part of today compared to the early 80s as portrayed here is that ultimately the community sided with decency and working together whereas now it seems many of these types of communities have gone over to the McElroy side.