That describes it to a T -- at least the North, from my experience. While New England is truly frigid when it comes to interaction with "aliens", I am not sure where the social disconnect in the rest of the Northeast comes from... before I came to the US, I had tens of close friends. Now I have maybe 5 (if you count friends in distant parts that I meet occasionally) to none (in terms of motorcycle wrenching buddies). However, putting aside the machismo of NY/NJ culture, I do not believe this to be a result of racism. It could be cultural differences, my own attitude(s), an inherent aloofness in the US psyche (ha! there I go psycho-analysing, after critiquing Doug/ Galloway for it), etc. Wojtek summarised my fate (and his) fairly well in a post a while ago...
Someone mentioned that the racism in the North is polite while it is open in the South. Similar things were written by others. But I am not sure I (either) understand (or) agree. Southerners (the non- redneck single white male with gun-rack pickup truck variety) pride themselves on their politeness, etc, but have said the most racist things in the sweetest of terms to me. As Carl points out swimmingly, they seem to still exist in an environment where such expressions and actions (the celebration of the confederate flag) are yet to be considered impolite (leave alone forbidden, as in the North).
--ravi