Because it has been what he wanted all along. We are fortunate in that he was thinking with his gonads too much during his terms in office. I believe it saved us from some really damaging decisions. Not that the ones he made weren't damaging enough, but he didn't have enough political capital to change things as much as he wanted to. That's why Hillary stayed mad at him; not because of his philandering, but because he ruined the chance to take this country down from its position of superiority in the world.