By Richard Downes, Washington Correspondent

Hurricane Isaac caused some problems for the Republicans in Florida and this week it is just a matter of rain.

Storms, thunder and lightning are promised for Thursday, so the Democrats have had to shift from the newly refurbished stadium in downtown Charlotte to the much smaller Time Warner Arena. 

It’s a small matter of 50,000 people. That’s the difference in the capacities between the two venues. So at the very least there are 50,000 individuals who will be cancelling plans to travel to Charlotte.

Frankly the Democrats cannot afford to annoy anyone at this stage of the campaign. The race is so tight and so difficult for them in so many states that any slip up could be fatal.

The Republicans are trying to exploit this by saying the reason they are shifting to the smaller venue is that they cannot fill the stadium. So jaundiced is the Democratic faithful, they say, that the President couldn’t fill it.

Nobody trying to be objective really believes that. But all the Republicans are doing is trying to put a spanner in the works and to sow enough doubt, so as to take the shine off the Democrats’ day in the sun.

It’s an age old strategy. Similarly the storm in the teacup over some words that should have been put up on the stage at the Arena (but weren’t) could also alienate some voters.

The two words were Jerusalem and God. Enough said.