If the US presidential election was decided by money alone, Barack Obama would already be choosing what pictures to hang on the Oval Office wall.

The Democratic candidate has raised more than $400m (€270m, £215m) since launching his campaign last year, dwarfing the $170m collected by John McCain, his Republican rival. In July Mr Obama’s $51m haul was nearly double the amount raised by Mr McCain, leaving the Democrat with $68.5m in the bank compared with his rival’s $21m.