It used to be uncut guys in the US were mostly poor, foreign, or minorities. Then, a few decades ago, add in the liberal/hippie subculture. Recently, wealthy and well educated Americans have gone the way of intact. It would seem the last of the holdouts remain in trailer parks, or are otherwise entrenched in very conservative/white/religious subcultures. It has surely dropped to below 50% for newborns today. On the west coast, it's more like 30%. The highest rates are found in the south and midwest.
The problem with the change is that people seem to be taking up arms to defend their status and their decisions regarding their sons. It is undeniable that the circumcision advocates are losing, and will ultimately lose this battle. In the meantime, it's brutal to hear the arguments.