How does the language of the preamble reflect the idea of the social contract?

A brief introduction to a speech is a preamble, it comes before the Constitution like the Preamble to the Constitution starts out "We the People of the United States of America, in order to form a more perfect union ..."

Here "we" shows not a one person, it shows the whole social society which are coming together to establish peace, justice, equality etc. That’s how the language of the preamble reflect the idea of the social contract.