He's an accident waiting to happen
That's what people warned David Cameron when he hired not just any former editor of a muck-raking tabloid, but one who'd resigned after his paper created a scandal all of its own.
Today some are saying "I told you so". Some are asking questions about David Cameron's judgement. The prime minister has, though, only one regret - that a man whose judgement he has come to depend on has felt it necessary to resign.
Andy Coulson's value to David Cameron was not only as a mere spin doctor, nor as just the link man to the powerful Murdoch Empire, but also as someone who connected him to those who read, rather than produced, tabloid newspapers.
The boy from Essex was willing to stand up and contradict the prime minister's other principal adviser Steve Hilton - king of the Notting Hill set of metropolitan, intellectual and wealthy friends.
Today's resignation was meant to separate David Cameron from the phone-hacking scandal.
It will also separate him from someone with an instinctive understanding of the world beyond Westminster.
If Andy Coulson's advice is not replaced that really could be an accident waiting to happen.