You've probably been hearing this term a lot in recent years as major figures like Trump and Sanders have emerged and garnered massive attention on the national stage.
Well, political scientists say that we can look at society as being made up of two groups that are at odds with each other. The first group is the vast majority of common, "ordinary" people. The second group is the lofty and often "corrupt" elites.
A populist candidate, such as Trump or Sanders, seeks to focus a political message on the masses of common folks who represent the "general population." Thus, they are appealing to the majority of "the population." That makes them "populists."
Note that a populist can be a far-right kind of politician or a far-left politician. A populist can be viewed as both corrupt and evil or honest and enlightened.
For example, Adolf Hitler was certainly a populist because he pitted the common downtrodden German citizens of his era against those he framed as the corrupt and controlling elites. For Hitler, that included the various monarchies of Europe he felt were taking advantage of Germany. Unfortunately, Hitler included Jews in the category of corrupt elites.
But the point is, to be a populist should not be confused with an influential person who is "good and popular." For example, Cuba's communist dictator Fidel Castro was a populist, and so was the racist Alabama governor and presidential candidate George Wallace. Castro was leftwing, and Wallace was rightwing.
On the other hand, consider Lech Walesa, the Polish labor leader and later Polish president. He helped defeat the Soviet Union to free his nation from communist rule. Walesa was a populist.
Another example might be the former U.S. President Teddy Roosevelt. Although his legacy is somewhat controversial, he is generally viewed as a force for good by historians. Teddy Roosevelt was a populist.
Keep in mind that scholars define populism in more ways than one. For example, some historians and political scientists define it as simply when the "popular engagement" of the people is taken into account in political decision-making –- in short, simply doing what is "most popular."
