If I Hear the Term, "Covid Denier" One More Time...

One of the cheapest stunts you can pull in an argument is to side-step the issue at hand and instead cast aspersions on the character, integrity, or competence of your adversary. If someone is constantly vilifying the character or credentials of someone they disagree with, this is a sure sign that they either cannot, or do not want to engage in any substantive, evidence-based argument.