Must the term "populism" automatically be derogatory? Why do our democracies render themselves less democratic by rejecting the very notion of tolerance so foundational to them?

The term "populism" is, first and foremost, an insult, used today to describe political parties or movements deemed to consist of idiots, imbeciles, even lunatics. If they are animated by an idea or a program—the very subject of this book—then it is assumed to be an idiotic idea or program. "Idiotic" is intended here in both senses, modern (imbecilic) and ancient (idiosyncratic). In our current understanding of the populist phenomenon, these two meanings distinctively correspond and overlap.
There is a certain strangeness to defining a political current by its imbecility, especially in a democracy where, in principle, pluralism and tolerance for different opinions presides. There is, in the label "populism," a refusal of democracy. This book asks the question: why do our democracies become less democratic in these instances? What is so threatening about the movements accused of "populism" that they should be excluded from the common tolerance so dear to democracy?
(ne pas modifier quand meme, sorry)