Both had the goal of entering the White House together. In episode three of season three, Frank and Claire get into a very aggressive argument. Claire told Frank that she no longer wants to be a part of his life because it wasn't what she expected. Frank then explicitly explains all the hard work they've done together to get to this point. He was getting very angry with her because of her change of heart. The conversation ends with Frank choking her and making sure she gets his message. Frank uses violence and aggression to show his dominance over Claire. Claire isn't the only woman to be this way