OK, what I thought...
I figure Kushner or someone told him, "Dude, if you lose this thing, you're going to jail, so you better follow a plan."
He was effective in some parts (set aside the phony bully bravado), but his personal hatred of pretty much everything comes oozing out of the screen. Biden was trying to be a milder Bush 41 tonight (and he was a terrible debater), but I thought he did okay.
There's no good trite answer to the "eight years" punch because it requires engagement of the audience. Biden did better, though, when he went with, "it was a Republican Congress."
I think he should have gone with this:
"The biggest reason we couldn't do it in eight years is because your party wrecked the economy so bad that we spent years fixing it so we could hand you a great economy, which you went and wrecked with your refusal to listen to scientists. As part of that, we had to work on health care, which you're trying to undo as well. Things take time, Don, particularly things we know are complicated."