Earlier quoted context omitted.
> the author seems to be well versed in the memes of the US political discourse that's not exactly hard for anyone that payed even a little attention during the very controversial US political season in 2016. Same with Brexit. The terminologies and crux issues have been widely debated on the social web. I would say it has actually been very difficult to escape
Right. However, things like "caucus" and "SCOTUS" are really unlikely to be written by a Russian, on any English knowledge level. We do make mistakes, but our mistakes are different. In this text, there are too few common mistakes, and too many strange things.
What a weird thing to say. Even the most native of idioms can be learned, and there are plenty of fully bi-tri lingual people in the world.
Mining the text for cultural clues is a fool's errand.