Us vs. Them

Those of us who have been following the news, have seen a sharp increase of homicides in South Central L.A. Innocent people, gunned down.
Today, in the Times, it seems a sort of gang induced ethnic cleansing has been taking place. Latino gangs targeting African Americans, which correlates with what we've heard taking place.

Over on an excellent blog, Political Grind they've been talking about how immigrant groups are no longer striving for the larger mainstream. It seems to many that we're more separated than ever. When a lot of us were growing up, sure, there were cultural differences. There were hyphenated Americans, but there seemed to be a mainstream we all wanted to join, help build and thrive in.

But it's not like that anymore. It's become increasingly each to his own, and us vs. them. What's your take on how the mainstream became a less desirable place to work, live and do commerce in?