On the debate, Harris came in with a plan to stay calm, say very little substantively and bait Trump into going off the rails. Any other sane Republican would have crushed her on the issues.
I wouldn’t make the case that Harris “won”. She didn’t respond to many of the questions, and didn’t really convey a strong understanding of many issues. In any other year, she would be viewed as a very bad candidate. Standing next to Trump makes her look a lot better.
Much easier to make the case that Trump lost though. He was unfocused, took the bait from Harris every single time and just sounded crazy at times.