This is only part of Trump's positioning (and, in fact, his supporters love him for exactly this reason).

The biggest problem Trump faces is that he ran the first time on his promises, and now he has to run on his record.

It's tough to sell yourself as a master chief executive - "I alone can fix it" - when 175,000 citizens are dead on your watch and millions are out of work and struggling.

In this area, Biden has a significant strategic advantage: "If your opponent is defeating himself, don't interfere."

Your piece was written before Biden's DNC speech last night, in which he did well enough to alleviate most concerns about his mental acuity. (And tactically, the Republicans made an error in setting the bar so low for Biden's performance.) If Biden also performs well in the debates, these "What happened to Biden?" videos won't mean much.

As a positioning consultant myself, I think the Democrats framed the issues well last night. ("Judge this president on the facts"; "We will never have our lives back until we deal with this virus.") Trump is most vulnerable on his record, and the Democrats should keep hammering away at this.