Well, the first, easiest, and best thing to do for someone like this is to simply ask him to back up anything he says. Ask him to provide any sort of evidence that supports what he’s saying. Or hell, even just explain what he’s saying. As in, define his terms, etc.
Thomas Sowell says it quite simply:
“There are three questions I think would destroy most of the arguments on the Left:”
- Compared to what?
- At what cost?
- What hard evidence do you have?