Editorial: An unknown electoral quantity named Sandy

With the north-eastern seaboard of the US battening down the hatches, flights grounded and the New York Stock Exchange closed, both presidential candidates might ruefully ponder Harold Macmillan's fear of "events, dear boy, events".

For, as events go, the threat of hurricane Sandy storming in just a week before polling day is a very big one. Even if it turns away at the last minute, it will have left its disruptive trail, not just in physical damage.

The stakes are higher for Barack Obama. He has to show his presidential side – or fail miserably, as George Bush did with Katrina; how he copes could decide the election. Mitt Romney can only wait out the storm; campaigning – even in the handful of swing states – would seem insensitive, especially now Mr Obama has, rightly, returned to Washington. With weather eclipsing politics in the American media, there are suddenly three in this contest – a President, his challenger, and Sandy – leaving the result even harder to call than it was.