Rights are essentially a treaty of peace between individuals. The fairest such treaty--and therefore, the one most easily negotiated--is based on reciprocity and symmetrical equality.
"Don't claim rights for yourself while denying that I also have them; don't expect me to respect rights you claim for yourself that you don't respect for others."
That's the only valid "social contract." That's the peace treaty I'm willing to make with anyone and everyone. I might be willing to negotiate some other treaty, but no treaty or "social contract" binds me unless I consent to it.
Liberty is the null hypothesis, and as such requires no proof.
It's the one who seeks to rule, to control the lives and choices of others, who is required to prove he as any rightful authority to do so.
Prove that the US government has any right to rule. Prove that anyone has any right to bind anyone to a Constitution without their explicit consent. The burden of proof is on you.
My right to liberty follows inexorably from your inability to prove any right to rule me.