Who would want to be Barack Obama in Copenhagen this December? Mr Obama's election last year was the cause of much delight around the world since it signalled that the US was finally ready to talk seriously about global warming.

But Mr Obama, who is the first US president to push strongly for Congress to enact cuts in its carbon emissions, is beginning to suffer from the problem of high expectations – an exact reversal of how George W. Bush was treated.

Unless something miraculous happens on Capitol Hill, Mr Obama is almost certain to undershoot expectations at the climate change summit in Denmark. Some time in the next two weeks, liberal Democrats will introduce a cap and trade bill in the Senate that will unleash the latest bout of in-fighting within their party following its continued divisions over healthcare reform.