The population numbers are a bit misleading...those percentages come from the official census. Now, if you're in el-Lay, you gotsta kno, someone knocks on the front door of a house with LAtinos living in it, more often than not there's about 15 people heading out the back door. Least, that's how it goes down here. The census may say theres 26%, but in reality, you can probably double those numbers for Latinos.
As far as the rest, only about 29% of all households have kids under 18 living in them. Now, even if you just go by straight numbers, which isn't even close to being the case, you don't end-up with a helluva lot of White kids relative to the population in general. Right now the public school system runs, I believe, about 3-5% White, as a whole, and that includes magnet schools and like that. The recruit pool is pretty slim.
The numbers are further whacked by the policy of bussing existing in the city. Where neighborhood schools were once the rule, and neighborhoods remained fairly homogenous, now kids are bussed all over to achieve "integration", and as a result, neighborhoods have been broken up.
Are ther "White" clubs left in the city? Yes, there are. Some are so small as to not even have names, but they are still in their traditional neighborhoods. One of the big reasons you don't see the numbers and the noise about them is that they aren't involved, in an organized fashion at least, in the drug trade. Say what you will, it's the cash generated by sales that has fueled the growth of street gangs as they exist today.