Which political principle is set forth in this quote from the declaration of independence? "that whenever any form of government becomes destructive of these ends, it is the right of the people to alter or to abolish it, and to institute new government ... "?

Answer: Social contract theory

Explanation:

After asserting the natural rights of mankind, saying that "all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness," then the Declaration of Independence goes on to give a list of "facts to be submitted to a candid world." These facts were meant to demonstrate that the British king had been seeking to establish "an absolute Tyranny over these States" (the colonial states which were declaring their independence). This was a violation of the social contract which exists between a government and those governed.

The Declaration listed such grievances to support the colonies' position that tyranny was standard operating procedure by the British monarchy, and therefore revolution was justified. This was based on the idea of the social contract, that a government's authority to govern came from the people, and if the government did not serve the people properly, it could be replaced. The Declaration asserted that principle in these words: "When a long train of abuses and usurpations, pursuing invariably the same Object, evinces a design to reduce them [the people] under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security." [That's the larger context of the passage quoted in the question.]