Were you alive back then? As I remember it, he was a perennial also-ran because he couldn’t help but stay stupid shit now and then

Actually, yeah.

But why does that matter? Sure, Biden is old, but his first presidential.primary isn't ancient history, we don't have to have actually seen it to know about it.

Biden was initially considered one of the potentially strongest candidates as campaigning began in 1987.[6] This was because of his image as a political moderate, his speaking ability on the stump (rated second only to that of Jesse Jackson), his appeal to Baby Boomers, his high-profile position as chair of the Senate Judiciary Committee, looming for the Robert Bork confirmation hearings, and his fundraising appeal—his $1.7 million raised in the first quarter of 1987 was more than any other candidate.[7][8] By the end of April he had raised $2 million, using not just contributions from Delaware but also establishing a base of support among young professionals and Jewish voters in a number of urban- and suburban-oriented states.[9] He had no campaign debt, and Fortune magazine termed his "most impressive start" a "surprise".[9]

https://en.m.wikipedia.org/wiki/Joe_Biden_1988_presidential_campaign

The only speaking difficulty Biden has had up till the last decade, has been when media press him on a challenge, he gets pissed and starts insulting them. The deathblow to the 88 campaign was when his speech plagiarism lead to reporters finding out he cheated in school and lied about being active in the civil rights movement.

He might have survived that, but he started insulting reporters when they asked. A pissed off presidential candidate yelling about how much better he is than the worker man sells a lot of newspapers and it's a vicious cycle that's hard to get out

He was still doing it last campaign, he'll do it next time.