It'd be like trying to talk to a 9/11-truther or a flat-earther, they'll have a refutation ready for all of your evidence, or they'll convince themselves your cited sources are part of the conspiracy..

They'll use any excuse to delude themselves that they're correct, because to admit otherwise is to admit that they were dumb enough to have been conned by a terrible conman. When they saw the morons attacking congress, they convinced themselves "people wearing helmets are Antifa, and all the attackers are Antifa plants...".