Final answer:
Popular sovereignty is demonstrated by the authority of a government derived from the consent of the people, as in the example of Lewis Cass's election and the foundational principles of American government. Referendums and elections are practical illustrations of this concept, where citizens have a direct say in legislation and representation.
Step-by-step explanation:
The concept of popular sovereignty is illustrated by the principles that the authority of a state and its government are created and sustained by the consent of its people, through their elected representatives. This principle is evident when analyzing historical examples such as the election of Lewis Cass, a proponent of popular sovereignty, whereby citizens in a territory had the right to decide whether slavery would be permissible. Other examples include the fundamental aspects of American government, where leaders are elected by the people to represent them and are only considered legitimate as long as they fulfill the social contract, deriving their power from the United States Constitution.
In a practical sense, examples such as referendums and the election of government officials embody the idea of popular sovereignty, giving citizens direct control over legislative decisions and who represents them in government. This concept is also echoed by James Madison's view on republicanism, stating that a government derives all its powers 'from the great body of the people' and is a system that limits power to representatives elected by the people.