Despite the posturing, strategising, marketing, skulduggery and other machinations that form the dark art of politics, it comes down to plain luck. Some politicians are born lucky, some create their own and some have it thrust upon them. Mrs Thatcher, for instance, had luck be a lady for her when the Falklands presented itself halfway through her unpopular first term. Nothing unites a country as much as a common bogeyman. And if there's one thing better than the 'immigrant threat', then it's a hostile military aggressor.
There's little doubt the PM and George Osborne were born lucky, but they've been surprisingly lacking in the creating-their-own-luck department. David Cameron has been unusually prone to a succession of U-turns where a policy initiative that appears to be offered up on the hoof (it surely isn't?) backfires: from pasty tax to fuel duty to the booze levy, and so many more.
This week both the PM and his Chancellor got lucky. Osborne's heinous bedroom tax has been all but forgotten as the attack on the so-called benefits culture has crystallised shamefully, with a huge leg-up from the Daily Mail, around the 'vile' figure of Mick Philpott. It doesn't matter how irrelevant the Philpotts are to the wider debate, they have now become emblematic of it.
The PM? His luck came from further afield, via the bellicose new North Korean leader, Kim Jong-un. Nothing concentrates a western mind like a rogue state's new leader authorising a nuclear attack on America. And who happens to be arguing the previously ever-weaker case for Trident? Ed Miliband should be so lucky.