The second defining principle of the tea Party is its unapologetic defense of U.S. sovereignty. Tea Partiers believe that the United States has a right and a duty to defend its geographic territory and legal independence from other nations and supranational entities such as the United Nations. The sovereignty principle is evident in several issues of importance to the Tea Party, including the war on terror, immigration, and the role of international law in applying and interpreting the U.S. Constitution. Before diving into these controversies, however, it's useful to discuss what sovereignty means, why the Tea Party thinks it's so important, and what could happen if it's lost.

In its most basic sense, sovereignty is power. Power over what? The power to make, interpret, and enforce law. This is why God is often referred to as a sovereign, because Christians and Jews believe he made, and judges compliance with, the Ten Commandments. In secular terms, sovereignty is concerned with man-made laws that are understood and acquiesced to within a specific geographic territory. In any given geographic area, the people residing there will recognize a person or group of persons with the power to make, interpret, and enforce law. This sovereignty may be parsed among multiple people or entities, each with limited and defined spheres of power. In the United States, for example, the Constitution divides sovereignty between a law-making branch (Congress), a law-executing branch (the president), and a law-interpreting branch (courts). Each of these branches has a share of sovereignty, but none possesses the whole of it. Dividing sovereignty horizontally, among various branches of government, is one way to check against tyranny.