Late Stage Anglo-American Empire

Personally, I think it's most likely to happen after the US loses control of a significant portion of its empire and has to resort to using its harsher policies domestically. We're exploited here, and we're aware of our evils abroad in a vague way, but I don't think that's really going to sink in for most Americans until they're having to deal with at home, live under the full extent of capitalism's evil, and realize that it can't be rehabilitated.

I think it's more likely, however, that the US could step back from fascism, even be restructured. But even then, I suspect whatever follows would just be shades of liberal and capitalist.