Defining populism is very difficult; the term itself is unstable and controversial. Ernesto Laclau notes that political movements always overlap with other ideologies; therefore, populism cannot be defined by its content, ideology, or social base. He argues that populism is a political logic or a way of constructing the political. In other words, when trying to understand populism, scholars should understand how it works rather than what it is. Laclau identifies the key structure of populism as:

(1) Social demands: issue or request made to the state or other government bodies

(2)Formation of a "Chain of equivalences":  people start to connect grievances to a common cause 

(3) Empty Signifier: A vague symbol that unites diverse groups 

(4) The people:  A new group emerges called "The People." This constructed group opposes the government elites