I think I understand what he is saying. In the town where I grew up, the Hispanic people there all acted gangster. They were tough guys who floated in and out of jail. If you go to other towns though, you'll see that Hispanic people are actually quite normal.
The thing I have noticed is that the first and, sometimes, second generations of Mexicans here in the US are generally very hard working and "normal" people. But by the time you hit 3rd generation and so on, they start turning into thugs and becoming people who are really problematic. I know this is a bad generalization, but it seems to be somewhat true from my experience in my town.
This summer I worked in a manufacturing plant. I was the only white person there, everybody else was Mexican. Most of them were actually from Mexico, but almost all of the rest were second generation. A lot of them were complaining about how their kids were awful and in gangs. Even these Mexicans, who were awesome normal people, agreed with me that their children are awful people and don't fit into society. From what I gathered, it seems to be the whole gang life thing. As a kid, you have to join a gang or people will beat the crap out of you all the time. Once you're in that gang, you can't leave or they will beat the crap out of you all the time or even kill you in extreme cases.
I really don't know what else to say about this. Of course, this all only applies to my town where I grew up. I've been told that the Hispanic people in places like El Paso and San Antonio are actually quite normal.