Well I was born in Studio City, CA, and moved out to Illinois when I was 9 months or so, to the south suburb of Park Forest, and I became a Sox fan. When I moved back to california, in 1995, I moved to Burbank, and was still a Sox fan.
I can tell you right now, it may not be the case on this board in particular, but the reasons that there are a lot of Sox fans, and Cubs fans, at Dodger/Angels games is because of one word...Hollywood. All the actors from Second City, and the Improv Olympics, come from there to here looking for work, and they already have ties to the Sox or Cubs or Bears or Bulls or Hawks.