Given that Jefferson was writing about a new democracy, do you think his language choice was appropriate?
While writing the Declaration, Jefferson used many words that were not in the everyday vocabulary of typical American colonists (an example is the word inviolable).
Beyond what the above post suggests (all of which I absolutely agree with), Jefferson's diction in the Declaration of Independence is absolutely appropriate for a new democracy. His use of language is both high and resolute, grounded in the fundamental beliefs of the Second Continental Congress.
In your question, you point out that his use of words that may not have represented the everyday American's vocabulary, but if Jefferson were to have lowered his level of vocabulary to be more approachable to the masses, then certainly some of the meaning and grandeur of the overall message of the Declaration would have been lost. Democracy gives the people a voice and a right to choose, but in no way, shape, or fashion, should Jefferson have 'dummed' down the Declaration of Independence to make it more palatable to the masses. The Second Continental Congress and Jefferson labored to create a document representing our list of complaints about King George, and they did so with high style and a sense of poetic brilliance, making the Declaration of Independence the most well-written break-up letter in the history of the world.
I think that Jefferson's use of vocabulary was highly appropriate given the topic of writing about a new nation. There is much in way of Enlightenment terminology in his writing. Such syntax is reflective of the idea that human beings are capable of greatness and even perfectibility. The recognition of democracy in Jefferson's writing as a part of this makes sense. The language of natural rights, consent of the governed, as well as the idea of petitioning for redresses are all consistent with the Enlightenment terminology as well as the basic idea of starting something new. The vocabulary of Jefferson's work expresses hope, promise, and a sense of autonomy that reflects both political and spiritual possibilities. It is here where I think that the word choice and basic ideas behind starting a new democracy makes both convergent and highly appropriate. Jefferson understands that, to an extent, he is helping to give voice to a nation's beginnings. It is here where I think that the syntax and word choice becomes significant and quite appropriate.