It’s pretty effective! The present-day soundbites in the clip below really are some of the most concerning that Biden has produced since becoming a candidate. If you’re a casual voter who strongly dislikes Trump and were thinking of voting early for Biden, maybe you watch this and say, “Hold on. I need to see this guy debate first.”

But I do think that’s the most Team Trump can hope for from this ad. It’ll pique people’s curiosity about Biden’s mental condition, but it also risks setting the bar so low for the debates that Biden “wins” simply by being able to form coherent sentences. The spot works inasmuch as it may convince people to withhold judgment on his fitness for office for the moment.

It also invites Biden’s ad team to respond in kind. I’ve mentioned before that if you watch TV interviews with Trump from the 1990s that touched on politics, he was more nimble on the issues and engaging than he is now. Trump’s campaign might reply that that was 25 years ago; the ad below shows Biden deteriorating much more rapidly, in just five years or so. True, but if Democrats can convince voters that Trump’s “lost a step” too, at whatever gradual pace, they might successfully neutralize Trump’s “dementia” attacks on Biden. That ad wouldn’t be hard to assemble: Show him slowly descending the ramp at West Point, clinging to Theresa May on the stairs during their summit, drawing baffled looks from reporter Jonathan Swan by insisting that the U.S. has one of the world’s best mortality rates, babbling about how well he scored on his cognitive test, and so on. The mysterious unplanned trip to Walter Reed last year, allegedly part of his annual physical, would also likely be featured.

All politicians have moments when they’re tired and seem addled (remember Obama’s “57 states”?). It’s easy enough to find those moments for a 70-something politician and put together a “this guy has early Alzheimer’s” innuendo ad about it.

Although, admittedly, it seems a little easier in Biden’s case.

Sounds like Trump’s putting his top men on this line of attack:

The Biden campaign is reminding people today that in a Monmouth poll taken in July, more Americans said Biden has the mental and physical stamina to do the job (52 percent) than said Trump did (45 percent). But we shouldn’t read too much into that: 52/45 is similar to the polling on the presidential race itself, which means people may have been treating that question at the time as a simple proxy for “Do you prefer Biden or Trump?” Lots and lots of Americans, I’m sure, are following the campaign only casually and haven’t heard any buzz yet about Biden’s mental condition. If Trump aggressively pursues this angle, people may start thinking about Biden’s fitness more and the next poll on “stamina” might look different.