gang members exist for the same reason the yakuza or camorra or russian or irish mafia exist...
when an "out" group is forced to create it's own dynamics for survival..
they form a very authoritative hierarchy that takes "masculine" human roles to the extreme:
provider - hustler - organized moneymaking
protector - enforcer - organized violence
end result is organized crime
Salvadorean immigrants fleeing civil war end up in the middle of a new country
and surrounded by that country's discrimination and gang problem...
over the years creates one of the most well known and vicious gangs
it's a societal issue that will take government and civilian effort to reverse...
Japan is just now getting to the point where they are breaking down Yakuza structure and influence...
and they been active for hundreds of years
I know gangs in south central arent as organized as the bigger organized crime syndicates in the world...
but upper level members of those gangs hold a lot of influence and money making ability...
that is backed by the abundance of their foot soldier crash dummys