Andrew Mitchell certainly did hang on and hang on for a very long time, but why go now? Because he realised he had become the poster boy for what people most dislike about this Government.
What is not in doubt about the government is that it is taking tough and unpopular decisions and the difficulty is that you can survive lots of things in politics, but if you become the symbol of peoples resentments against that government then you really are in trouble.
What is most interesting about tonight is that he has adamantly come out and denied using the word 'pleb' which was the one that was so toxic.
David Cameron admits it 'became apparent' to the former Chief Whip that he could no longer do his job. So why was it not apparent to the PM?
Government Chief Whip Andrew Mitchell has resigned after swearing at police guarding Downing Street.
Losing one's temper with a police officer would be excusable in most people, but for the Tory chief whip to do means so much more.