“Herein lies a lesson: A huge number of people have decided that there are a cadre of people who are so vile that any opinion they touch is immediately toxified beyond investigation. Claims are not to be evaluated on their own merits; instead, we can simply determine whether a claim ought to be supported based on those who posit it. This helps to explain why political crossover has become nearly impossible: We’re not judging the claims of our opponents; we’re judging each other. And this means that we can discard any argument simply by dint of the fact that we don’t like the person offering it. “