In other words, a socialist organization aimed specifically at the American diaspora. Perhaps as an overseas wing of a pre-existing communist party in the USA, or perhaps as its own wholly separate party/organization maintaining good ties with the better stateside socialist organizations.

The purpose of such an organization would be to provide analysis and address issues affecting the American diaspora in particular, to agitate for socialist ideas and against the two-party system in the American diaspora, to provide visibility for overseas Americans fighting against imperialism and colonialism, and to explore how overseas Americans can better utilize their status to this end. Things like this, at least. I think it could maybe be a nice thing, could be a little niche to fill.