The men who signed the Declaration of Independence represented the absolute opposite of "interest group politics" so slavishly worshipped in political science departments. They pledged their lives, their wealth, their liberty, and their honor -- everything -- on a toss of the dice. Often, even if the revolution won, these men personally lost. The game was not about them, their economic interest, or their political ambition. They won if America became a new order of liberty in the world. Interest politics would have led them all to make peace with the Crown. Moral principles led them to what Churchill would later call "blood, toil, sweat, and tears."
The brave men in Philadelphia were engaging in unconstitutional action. Britain had a constitution, albeit a largely unwritten one, and Jefferson knew that he was defying our equivalent of the Supreme Court. He and his colleagues defied the moral power of a system which no longer treasured liberty above advantage or caprice. Rulers making decisions which did not really affect them, living thousands of miles from their subjects, lacked the moral authority to wield law.
Moral authority was the heart of the Declaration as well. It lacked a separation of church and state and instead there was a unity of God and government. All men were created equal by God. That is the foundational point of the Declaration from which all else flows like the spring of liberty. If all men are created equal and endowed by their Creator with certain inalienable rights, politics is clear and simple. If that is true, then -- of course! -- protecting these inalienable rights is the only reason that governments are instituted among men. These were truths which, in the magical pen of Jefferson, the brave authors and signers held to be "self-evident." There is a Creator. He made us. He made us, specifically, free in body and in conscience. We are not sheep or some sort of oddly self-domesticated animals. We are creatures in the image of a Creator, unique in reality, and given the power to choose.