At the end of the third season of House of Cards, Claire Underwood announces that she is leaving Frank, ostensibly because she can no longer stand his condescending and abusive behavior.
But I thought that for a political animal as shrewd and as ambitious as Clair Underwood, she won't walk out on her President cum husband just because she is angry, no matter what. She should know how to control her emotion and swallow whatever that is coming at her. At this point of time, she needs him more than he needs her to get to where she wants to be (presumably the President of the US)
Plus she made a deal with Frank, they are supposed to help each other to get elected. If she walks away, she will get nothing.
So I think the whole plot simply doesn't make sense. Is there a better explanation on why Claire would leave Frank in a heartbeat?