House of Cards, as explained by someone who does not watch House of Cards

Links to images:
Frank and Claire, inches away and hearts apart
Frank, Claire, Zoe, and that one gentleman Frank murdered 
For Frank and Claire, the devil is in the details. As a team, they wage war on the establishment in Washington, clearing a path to power much like General Sherman cleared a path to the sea. Drawn together by ruthlessness and a seeming lack of a moral compass, Frank and Claire are the perfect duo. That is to say, the perfect duo to leave a man in his car to die of carbon monoxide poisoning, and then fake their sympathy for his death. But these are secondary details. Yet as they build a fortress around Frank's reputation, this discreet Bonnie and Clyde duo face their own internal battles. Distrust, Siberian-cold-personalities, and poker faces of stone often turn Frank and Claire against one another. The couple often cheat on one another (and they both know it). These extramarital affairs, such as Frank's ultimately murderous affair with Zoe, and Claire's interest in that one artist fellow, seem to render their mutual cause asunder. In these moments of separation, Frank and Claire push each other apart, and go to wage their own battles. There is an intangible black hole swirling between them, driven by that same distrust they target at their opponents like high-powered laser beams. Peace (and perhaps even understanding) between them is intangible, much like the climate of Washington itself. Yet, like the pull of a black hole, Frank and Claire are drawn back together. Their individual struggles are fused together, fueling their crusade against the other political elites, and burning a path to the top. It is true: the best relationships are based on hating the same things together.