Definition
Popular sovereignty is the principle that the ultimate source of governmental authority is the people themselves. Government is legitimate only because the governed have consented to it and may, through lawful means, reshape it.
The U.S. Constitution embodies this idea from its opening words. The phrase We the People announces that the document is established by the people rather than granted by a monarch or imposed by force.
Why it matters
How it works
In practice, popular sovereignty is exercised indirectly. The people do not govern day to day; they choose representatives, who legislate and administer within constitutional limits. Periodic elections renew or withdraw that consent.
The Constitution itself was put to the people through ratifying conventions, and it can be amended only through procedures that ultimately rest on broad public agreement. Sovereignty thus operates through structured institutions rather than direct rule.