The correct answer to this open question is the following.
The word "necessary" was important to the drafters of the Declaration of US Independence in that it was the most specific word to be used to transmit the idea that the colonist had no other choice but to break away, to be independent of England.
That part of the texts says: "When, in the course of human events, it becomes necessary for people to dissolve the political bands which have connected then with another, and to assume among the powers of the earth, the separate and equal station to which the laws of nature and of nature's God entitled them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation."
