Sandy colours the election campaign

Barack Obama is set to return to Washington earlier than scheduled on Monday to monitor the storm

Today President Barack Obama will wheel out his not-so-secret weapon, Big Bill.

But he's only getting one shot. He and Clinton will appear together in Florida. The former president's fact-packed defence of the current leader was the star turn of the Democratic convention and supporters are keen to see the two together.

But the people of Ohio won't get to witness the double act.

The huge storm threatening chaos in Washington, New York and the surrounding east coast has forced the president to scale back his campaign plans.

After the event in Florida he'll return to the White House to monitor what is happening, and will stay there until Tuesday evening, when he'll have another campaign event the other side of the country. That's the plan for now, at any rate.

Mitt Romney has also cancelled events planned for Virginia and moved instead to Ohio. He has also scrapped his plans for a Tuesday rally in New Hampshire "due to the concern for the wellbeing of residents in the path of Hurricane Sandy".

So the storm has already had an impact on the campaign.

Haunted by Katrina

In effect it means the icy rains predicted could freeze the election for at least a few days - the American media will report on little else and fewer voters will hear what the politicians have to say.

Mitt Romney has pulled out of a planned rally in New Hampshire on Tuesday

It is hard, if not impossible, to say who that will benefit.

Both candidates will be careful of their tone - it gives Barack Obama a chance to appear above politics and to look presidential - but any failure would be magnified, and problems tend to get blamed on the president.

At the moment of writing, the storm has not struck. Everyone believes that it will be pretty unpleasant, and of course those of us with family in the area are very concerned. It clearly has the potential to kill.

But, haunted by Hurricane Katrina, politicians are forced into a deferential abundance of caution.

I just wonder how this will go down in the rest of the nation. People in swing states far away from the east coast will of course have sympathy for the millions who are likely to be left without power and lashed by heavy rain.

They want leaders to lead. But Florida, Iowa and Ohio know all about deadly weather, and when they suffer, it doesn't always stay on the front pages for days.

If the worst is avoided, they may not appreciate it if the president and his rival treat chaos in Washington and New York like a catastrophe.