Final answer:
Thomas Jefferson emphasized the principle of popular sovereignty, based on John Locke's theories, asserting that a legitimate government operates with the consent of the governed and must protect the people's natural rights, as stated in the Declaration of Independence.
Step-by-step explanation:
Thomas Jefferson was highlighting the principle of popular sovereignty when he wrote that government derives its power from the consent of the governed. This principle is foundational to the concept of a democratic republic, where the authority of the government is maintained only through the will and consent of its people.
Jefferson drew on Locke's theories of natural rights and social contract to assert that the people had a right to establish and maintain a government that protects their rights to life, liberty, and the pursuit of happiness.
If a government fails to protect these rights, according to these philosophies, citizens have the right to alter or abolish it. This concept profoundly shaped the Declaration of Independence and formed the basis for American revolutionary and constitutional principles.