It comes up a lot in politics, the use of the term "populist." In the current sense, it tends to be applied to someone originally from outside politics--say, Donald Trump--who grabs the attention of the common people, more than the political elites.
Steve Babson will happily tell you that the term is being applied incorrectly nowadays. And to prove the point, he wrote a short and easy book about the ORIGINAL people who called THEMSELVES populists: Forgotten Populists: When Farmers Turned Left to Save Democracy.
Never heard of the People's Party of the 1890s? Those are the people who gave birth to the term, and Babson traces the story in a visit to the JX.