The Wire is obviously the best show about US politics.
The Wire is easily the best show in the history of television, period.
As for the thread's question, The West Wing and it isn't even close. It was extremely hackish (like any remotely political thing written by Aaron Sorkin), but it was good for what it was (and it wasn't really a show about politics, first and foremost). I'd argue that watching The West Wing because you want a serious show about politics is about as silly as watching Law & Order because you want to watch a serious show about the criminal justice system.
However, House of Cards has almost literally no self-awareness whatsoever. Despite all of the shows desperate attempts to use pseudo-cyncism to present itself as Very Serious Business (Netflix even tried to market the first season as a show that reveals "how politics really works" and "how Congressmen play the game when no one is looking" lol), it is really just Kevin Spacey twirling his mustache while playing a villain with all the complexity and depth of Snidley Whiplash.
I have to admit that Corey Stoll was excellent as Russo even if many aspects of the actual character and his storyline were ridiculous (and not in a good way). But his performance was basically the only good thing to come out of the show.
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