Hardly anyone really talks about the right of the people to abolish an unjust government any more, but to the Founding Fathers it was quite a big deal:

I That all men are by nature equally free and independent, and have certain inherent rights, of which, when they enter into a state of society, they cannot, by any compact, deprive or divest their posterity; namely, the enjoyment of life and liberty, with the means of acquiring and possessing property, and pursuing and obtaining happiness and safety.

II That all power is vested in, and consequently derived from, the people; that magistrates are their trustees and servants, and at all times amenable to them.

III That government is, or ought to be, instituted for the common benefit, protection, and security of the people, nation or community; of all the various modes and forms of government that is best, which is capable of producing the greatest degree of happiness and safety and is most effectually secured against the danger of maladministration; and that, whenever any government shall be found inadequate or contrary to these purposes, a majority of the community hath an indubitable, unalienable, and indefeasible right to reform, alter or abolish it, in such manner as shall be judged most conducive to the public weal.

- Virginia Declaration of Rights (on Wikipedia)

Fascinating how much more direct and to the point that is than either the Declaration of Independence of the US Constitution!