A big part of that, I think, is that he had been hyped so much, over the last two years. His PR machine was very aggressive and effective, and he sort of existed in a protected environment, having some early well publicized successes as governor with little opposition.
I can’t prove it, but I really get the sense that the left recognized that he was being groomed to take out Trump and went easy on him. At any rate, after being treated with kid gloves for the past two years, it was a real eye for many voters to see him in an environment where he wasn’t in total control.
“eye opener” not “eye”