Digs in first and then 'plants' the info - it's even worse.

Said it in defending someone against yet another Tbag insult. He was disqualified by some for being out of date, sexist, and threatening violence.
Doing it to our own is passtime. I'd imagine this was done to knee-cap him for a possible future run.

Biden said, in reference to Trump's unrelenting misogyny, that back in his high school days (some 60 years ago), a gentlemanly chap like himself would beat that scoundrel's ass. For some odd reason, a lot of the reporting of those remarks implied or said outright that Biden was talking about the here-and-now instead of 60 years in the past.

Isn't it odd, though, how some people's comments get fly-specked like that, but Trump says, clearly and plainly from the podium, that the crowd should "knock the crap out of" people who aren't cheering him lustily enough, and nobody says a word or even remembers it?

there are actually nice, decent people in the world.

The one (ugly hateful past) does not necessarily deny the other (nice, decent people). Different tenses allows for potential and valid variances in a future relative to the original verb tense.

That said, "ugly, hateful things in our past" (as implied in the OP) is much different than an "ugly, hateful past" (as you re-interpreted it). While we are all guilty of the former (except for saints and liars), we are not all guilty of the latter.

There was a MOUNTAIN of evidence of terrible behavior by Trump before the election, during the primary, during the general election and GOP voters DID. NOT. CARE.