Demagoguery is the art of the generalization. Because it is a generalization, one cannot disprove it. If you come up with a concrete counterexample, the demagogue simply dismisses it as "an exception that proves the rule" or as "an isolated occurrence", and continues blathering.

If s/he did actually get some balls and name names, s/he would sooner or later find him/herself on the business end of a libel suit (and would probably lose, which wouldn't help The Cause\ufffd much...).

You really need to brush up on your Goebbels 101....