In the dictionary, “demagogues” are bad by definition.

In Merriam-Webster, a demagogue is “a political leader who tries to get support by making false claims and
promises and using arguments based on emotion rather than reason.”

In the Oxford Dictionary, he’s “a political leader who seeks support by appealing to popular desires and prejudices rather than by using rational argument.”

In the Wiktionary, he’s a “political orator or leader who gains favor by pandering to or exciting the passions and prejudices of the audience rather than by using rational argument.”

In your calmer moments, though, it’s tempting to dismiss the concept.  In practice, isn’t a “demagogue” just a political opponent with a silver tongue?  Isn’t “demagoguery” simply rhetoric that hits political nerves you wish would stay eternally numb?

But before you ditch the whole concept, let me propose the following refinement: Demagoguery is the politics of Social Desirability Bias

The heart of Social Desirability Bias: Some types of claims sound good or bad regardless of the facts.  “Helping people” sounds good.  “Acquiring luxuries” sounds bad.  “Saving American jobs” sounds good.  “Cheap nannies for upper-middle class families” sound bad.  “Supporting our troops” sounds good.  “Sympathizing with the enemy” sounds bad.  “Raising the minimum wage” sounds good.  “Measuring disemployment effects” sounds bad.

Any competent philosopher can construct cases where what sounds good is bad and what sounds bad is good.  For instance: The minimum wage, good as it sounds, would be bad if it sharply increased unemployment of low-skilled workers.  But when our competent philosopher runs for office, he has a clear incentive to keep his doubts to himself.  If X sounds good, saying “Hooray for X” is a much easier way to win over an audience than “Sure X sounds good, but let’s calm down and consider the possibility that X is in fact bad.”

It’s possible, I grant, that X’s only sound good when those X’s are good.  If so, we can safely ignore Social Desirability Bias.  To test this optimistic view, I propose the following thought experiment:

Imagine we do vastly more X.  Could you then publicly declare, “We’re doing too much X” without cringing? 

If government spent ten times as much on terminally ill children, would you feel comfortable announcing, “Government is wasting money on terminally ill children”?  If government spent ten times as much on war heroes, would you feel comfortable shouting, “Government gives too much to war heroes”?  Don’t want to say such things ever ever ever?  Then the policy views you and your fellow citizens cherish are probably infected by Social Desirability Bias.

The same goes for the Panglossian view that “X sounds bad” solely
because “X is bad.”  Imagine we increased our anti-terrorism efforts
ten-fold.  Would that remove the stigma from saying, “Let’s relax our
anti-terrorist efforts”?  Not bloody likely.

What then is demagoguery?  Embracing Social Desirability Bias to gain power.  Making a career out of praising what sounds good and attacking what sounds bad. 

What’s the alternative?  Conscientiously searching for and publicizing the many disconnects between what’s pleasing to the ear and what’s true. 

You could object that no public enemy of Social Desirability Bias could succeed in politics.  While I tend to agree, that realization should terrify you.  Social Desirability Bias is a severe mental shortcoming, but to succeed in politics you have to feed it rather than starve it. 

I know these claims sound bad.  But if you reject them because they sound bad, you are only proving my point.