.NO PRESIDENTIAL dispute has had as much effect on a vote-casting as that between Joe Biden and Donald Trump on June 27th. Mr Biden's efficiency was so unfortunate that his very own gathering pushed him to quit. Considering That Kamala Harris, the vice-president, substituted him as the Democrats' nominee the race has actually firmed up. It is now a toss-up, depending on to The Economist's version. On September 10th Microsoft Harris will definitely encounter Mr Trump in a 2nd governmental discussion. The amount of variation will this set produce?