The thing about Biden, though, is that he's been like this as long as I can remember. Do we know for sure that it's actually getting worse? Not trying to defend him but if it's just the same old-same old the observations lose some of their urgency.
I'm inclined to agree. Biden was more or less equivalently gaffe prone two decades ago as a senator, and I don't see any convincing evidence it's gotten much worse. Many people in the new wave of the Democrat Party appear to be looking hard for this stuff, possibly merely a result of the competition in the Primary campaign.
My impression is that Biden has long been a fairly amiable and garrulous person, but one who lacks intellectual depth, or, as we used to say in the Navy, "He wouldn't float head down." .
My chief concern about Biden is the apparent, indeed almost flagrant, misuse of his position by his son to enrich himself, apparently through his father's international connections.