If you listen to enough of Dementia Joe Biden’s incoherent babbling, you invariably begin to ask yourself one question: What if Donald Trump had ever said any of this stuff? Let’s go straight to the audio. All dialogue guaranteed verbatim. First sound, from last Friday, at a military base. Joe is on stage with a service family, and he turns his leering attention to a young girl who appears to be of elementary-school age: “Margaret Katherine, I uh love those barrettes in your hair, man. I tell you what, I look at her, she looks like she’s 19 years old,...