Of course readers of The Devil's Highway by Luis Alberto Urrea could make the assumption that all the illegal immigrants trying to cross the American border are "good people" and all the Border Patrol agents (whose job it is to keep people from crossing the border illegally) are bad people--or vice versa. That would not be a true and fair characterization, however, because there are certainly "good guys" and "bad guys" on both sides of the border.
Urrea is a journalist who writes about a specific incident involving the Yuma 14 who died during a border crossing (or the Wellstone 26 which includes the survivors). While it is clear that he has a point of view--which is that the way things are being done is not working for either side of the border--he does not characterize one group as being good and the other as being bad.
There are both good and not-so-good people working in Border Patrol, just as there are good and bad people who harbor groups getting ready to cross, lead groups across the border (coyotes), or cross themselves. And that is the point, isn't it? If it were a simple matter of just getting rid of or replacing one "bad" group of people, then all the border and immigration problems would be solved.
Instead the issue is complicated by all the people, like Mendez (who kind of tries to help but is ultimately looking out for himself), who display both positive and negative characteristics. Urrea shares the stories of each of the men who were trying to cross so readers will know they are human beings with goals, hopes, and dreams, just like them. He also shares Border Patrol agent Mike F.'s perspective so readers can understand the realities and dangers of border enforcement.
Urrea writes that
"In the desert, we are all illegal aliens."
He is right, as the terrain is the enemy of everyone who lives, works, and crosses it. The most important thing for Urrea, it seems, is the need for everyone to see that something must be done.