The term refers to a person who favors government control of businesses that affects most citizens is POPULIST.
A populist person is someone who cares about the interests and opinions of ordinary people rather than a small group.
Trump expresses one aspect of populism, which is anger at the establishment and various elites. He believes Americans have been betrayed by those elites.
The term “populism” dates to the 1890s, when America’s Populist movement pitted rural populations and the Democratic Party against the more urban Republicans.
In the 1950s journalists began applying it more broadly to describe everything from fascist and communist movements in Europe to America’s anti-communist McCarthyites and Argentina’s Peronistas.