I know the argument you're making is one that is popular in the media right now, and you may even be right. Surely Harris would have been able to do better if she had started earlier--or maybe she would, but when 40 percent of the people in the country who watch news get that "news" on Fox, ... maybe she wouldn't. In any case, it's hard to blame Democrats for trying to stick with a president who successfully battled Republicans, avoided a recession, got us through COVID, and got more done for the country than any other modern president. Sure, the man was old and a truly terrible speaker, particularly because of his stuttering, but speaking ability is not all that important in actual presidential duties; it is important mainly in campaigning.
Throwing insults at Trump? No, I was stating truths about him.