(Haven't watched it, but seems his last episode goes off the chemtrails rails. Gosh, in some ways Tucker is such a rookie!)
Part of the problem why Tucker probably more easily falls for stuff like that is that he doesn’t seem to be very inclined to think like an engineer, scientist or builder. When you are more inclined to think that way you can easily come up with a whole array of justified and rather easy counter arguments that are hard to overlook in quite a number of the claims the chemtrail crowd is making including the guy he interviewed. I watched a couple of minutes and gave up because the guy is making statements and assumptions that can hardly square with reality at least in the way he is thinking about “chemtrails“. By the way, Candace seems to have similar tendencies of not thinking in engineering/science/building terms, and that is IMO likely the reason she is inclined to think the way she does about the moon stuff and also in things like what mechanisms exactly could have killed Kirk.