Closing the gap won’t be easy. Mr. Trump must prosecute the differences between Mr. Biden’s very liberal statements during the primary (e.g., “We are going to get rid of fossil fuels” and “I’m going to eliminate the Trump tax cuts”) and his attempts now to make those comments disappear. Team Trump has done too little of that so far. The president is a showman; he should be able to drive this home. For example, he could highlight problematic Biden statements by playing videos of them on a giant screen at his rallies.

The president must close on his strength—the economy—on which people trust him more than they do Mr. Biden. Gallup recently asked Americans if they are better off today than four years ago. An astonishing 56% said yes, despite the pandemic and recession. By comparison, 45% said yes as President Barack Obama’s 2012 re-election came to a close and 47% at this point in President George W. Bush’s 2004 campaign.

As for Mr. Biden, he continues playing the prevent defense, trying to avoid saying anything memorable as he flies to battleground states to meet with important subgroups of the electorate. But a location and a group are not a message. Nor are ads a substitute for one.