I agree with Nate that the emphasis on Biden's so-called gaffes are merely disguised attacks on Biden's age.
https://twitter.com/NateSilver538/status/1161983108805255168
Maybe anti-Biden Democrats — and the other candidates — think they’re being coy by using Biden’s gaffes as a proxy for concerns about his age. No reason to get tarred with allegations of ageism, they figure, or to risk offending older voters who turn out in big numbers in the primaries. (Also, if the candidate they prefer to Biden is Bernie Sanders, they have the further problem that Sanders is a year older than Biden at 77.)1 Show rather than tell, as the maxim goes: Plant a few seeds and let voters build a narrative about Biden’s age on their own, without you having to give them the hard sell.
This strategy might even work! It’s still fairly early, and Biden’s age is perhaps his biggest risk factor — bigger, in my view, than his policy positions, which are often more in line with the views of the average Democrat than those of the more liberal candidates.
But especially in the era of Trump — who, of course, has already begun to question Biden’s mental fitness — there might also be something to be said for saying the quiet part out loud. In a poll conducted shortly after the first debate, a lot of Democratic voters explicitly used Swalwell’s “pass the torch” language when asked an open-ended question about why they didn’t want to vote for Biden.
And they were much more likely to explicitly mention Biden’s age than to use vaguer responses, such as that he was “out of touch.”
There’s also risk to anti-Biden Democrats in drawing voters’ attention to gaffes or other incidents that voters view as relatively minor. Biden remains an extremely well-liked figure among Democratic voters; 75 percent of them have a favorable view of him, according to Morning Consult’s latest polling. So three-quarters of the electorate is going to start with a predilection against sympathizing with critiques of Biden. If those critiques aren’t really bringing the goods and instead seem like petty grievances, those Democrats may conclude that the case against Biden is a lot of hot air.
Meanwhile, if the false alarms continue — Democrats on Twitter or on podcasts predict Biden’s demise and the polls are unmoved — the media may come to view Biden as a Trump-like “teflon” candidate who isn’t greatly affected by gaffes and scandals. That could reduce their appetite for covering them in the future — even if more serious ones occur than what’s taken place to date.