LIKE BIRD-WATCHERS with binoculars, observers of America’s presidential race have had their eyes trained on the opinion polls to see whether they can spot a post-debate bounce for either candidate. Now they can.

Harry Enten, CNN’s data analyst, recently assessed the chances of Ms Harris winning the popular vote at 70 per cent, but her chance of winning the requisite 270 electoral college votes at just 50 per cent. Look to the seven key battleground states, and it is clear the race is still a toss up.