Demagogy is generally a method of convincing a listener by appealing to the person's common sense and leaps of logic. In this sense, demagogy is not a lie, since it doesn't use false facts directly, but rather brings the unsuspicious listener to draw the appropriate conclusion himself. A leader who does this for his own benefit is known as a demagogue. Demagogy is closely related to the logical fallacy, but unlike the latter, it sometimes has nothing to do with logic.
In the twentieth century populism gained an ominous character when dictators such as Juan Peron and Adolf Hitler used demagogery and populist rhetoric to achieve their privileged leadership positions.
It could be argued that none of these men were genuine populists because they usually saw the masses as not fit to govern for themselves and therefore their hierarchical style of leadership was needed to govern and regulate the behaviour of the masses.
Methods of demagogy
Numerical demagogy - mixing of incomparable quantities. For example, "our government has increased social spending by 5 billion dollars, while the previous government has increased it only by 0.4 percent." Obviously, the latter sounds like less, but one cannot be sure without an absolute value.
False authority - relying on the general authority of a person who is not proficient in the discussed topic. Example: "the professor read my book, and liked it very much". The fact that it was a professor of chemistry who read a book on anthropology is omitted.
For or against (bifurcation) - assuming that there are only two possible opinions on a given topic. Example: "Smith is not with us, therefore he is against us". The possibility of a neutral position or divergence is ignored.
Unrelated facts - bringing unrelated facts that sound in favor of the speaker's agenda. Example: "Our beverages do not contain sodium deoxycholate". This is probably true, but the mentioned chemical is a detergent, and should not be contained in any beverage whatsoever.
Emotional attack - an attempt to bring a discussion to an emotional level. For example, "Everyone is against me!", "Can't I be right just once?", "You are stupid!", "You are demagoguing!".
- B. Katzenelenbaum, "Demagogiya - opyt klassifikacii", Nauka i zhizn 9 (1989) - in Russian. Online version (http://www.n-t.org/nj/nz/1989/0902.htm)