AS SOON AS Joe Biden announced that he would no longer seek re-election, attention turned to his replacement. Mr Biden endorsed Kamala Harris, his vice-president and running-mate, and dozens of Democratic lawmakers and governors have followed suit. With the groundswell of establishment support behind her, she is likely to be chosen as the nominee at the Democratic convention next month.

It is highly likely that switching from Mr Biden to Ms Harris improves Democrats’ chances of retaining the White House. For most of his presidency, Mr Biden’s poll numbers have exceeded hers. Since his disastrous debate on June 27th, however, that gap has vanished. In polls taken before the debate, Mr Trump led Mr Biden by a margin of 45% to 44%, whereas he beat Ms Harris in a hypothetical race by 48% to 42%. Since then, she has cut this deficit to 48% to 45%, roughly matching Mr Biden’s shortfall. A recent survey by YouGov found that Ms Harris’s net favourability rating was minus 15 points, worse than Mr Trump’s, at minus 10, but better than Mr Biden’s, which was minus 20.