Alec Guinness owns Smiley. Just perfect. Absolutely gripping yet low budget [+] it actually demands that you use your intellect to keep up. If you haven't seen those I say whip up ye old torrent client and get some.
Anyways, I did say "too greatly". Someone up there says "no spoilers" so ..
https://www.youtube.com/watch?v=ezekuICeYlg&list=PLSpG6jj23V...
Watched with my father growing up, may even have some home copies myself.
EDIT: someone else mentioned Tinker Tailor (either the '80s BBC miniseries or the Gary Oldman movie - once again he's killing it) which is far more grounded. That might be more up your street? I enjoyed both a lot. Bleak as hell though.
It's called Realism.
I mean this is just American politics in general.