Many years ago Joe Biden bragged about his education and IQ and appeared to challenge someone on their IQ as well. It's not clear what the full context was or what triggered Joe Biden to say these things.
One thing is for sure, Joe Biden is a lot more clear in his speech, he's talking fast, he's on point, and he knows what he's saying and probably where he's at. Compare that to his speech today and he clearly appears to have lost a few steps.
What will it take for people to realize this is not about Trump vs Biden, but about Democrats pushing out the most wackadoodle guy they can find in front of their party with the vice president candidate Kamala Harris who people didn't even like as a candidate. In fact, she was rating low in her own state, so what makes people think she's likable now? Oh, because she's a Democrat? Well that's stupid.