For populists, "the people" are presented as being homogeneous, and also virtuous. In simplifying the complexities of reality, the concept of "the people" is vague and flexible, with this plasticity benefitting populists who are thus able to "expand or contract" the concept "to suit the chosen criteria of inclusion or exclusion" at any given time. In employing the concept of "the people", populists can encourage a sense of shared identity among different groups within a society and facilitate their mobilisation toward a common cause. One of the ways that populists employ the understanding of "the people" is in the idea that "the people are sovereign", that in a democratic state governmental decisions should rest with the population and that if they are ignored then they might mobilise or revolt. This is the sense of "the people" employed in the late 19th century United States by the People's Party and which has also been used by later populist movements in that country.