he two real problems here are with contract theory and the problem of the notion of “right”.
Contract theory and the sovereign
Let me address:
freedom exists in a negative relation to the State. This produces the contradiction which appears to be oblivious to most people.
Then why are our political laws based upon this negative view of the nature of freedom?
With respect to “The government making a law prohibiting itself from making a law restricting someone’s ability to speak = the right to freedom of speech.” there is the technical and the actual. The technical operates with the fiction that the “government” is the people. I will address the actual momentarily.
Remember in contract theory that freedoms are unlimited in Hobbes' state of nature, but are given to the sovereign, and the sovereign then dispenses liberties to the citizens. (Note, also, the Locke, from whom the framers of the Constitution relied upon heavily, was a contract theorist, following in the footsteps of Hobbes.) Liberties are a subset of freedoms
Only the sovereign has freedoms. The citizens never have freedoms, only liberties. The technicality and fiction is that the people are sovereign.
With your “freedom exists in a negative relation to the State”, I think the central issue is the mistake that a government as sovereign does not regulate the freedoms it already has, as in the freedom of speech. The government as sovereign says how much speech there will be (from all through little) in the form of a liberty that the citizens have.
Liberties granted by the sovereign may be abridged, of course, and they have, such as Holmes' “shouting fire in a crowded theater” case, or perjury. A sovereign I suppose can regulate its own freedoms, i.e., dispense liberties to itself, but this is hollow without defining who the sovereign is. In the case of the U.S. it is the “people”, but this also is problematical, as they have no relationship to the government save through representatives. This gets to my next issue about the actual of “The government making a law prohibiting itself from making a law restricting someone’s ability to speak = the right to freedom of speech.”
Who is the “sovereign”, then? Clearly, there is no philosophy of State in a liberal democracy. The State is a holistic being, an organism unto itself. As Hegel says, it is the only one having freedom, consistent with contract law. The people – are they sovereign? That representatives can and do vote against citizens' wishes is common. Logically and effectively, they are not sovereign. In effect, the representatives are sovereign. But, this gets more complicated when the Executive and Judicial branches enter. Such is a main problem with liberal democracies, where the result usually is anarchy, one of the three factions fighting against the rest and many times rendering different governance. It seems more elusive than ever who has the “freedom”. Who is in charge here? Of course it is contradictory to say that if the freedom already exists, there is no need to make a law saying that someone has it. A law only can restrict it, i.e., define a liberty.
The main problem with “rights”, and as Hegel describes, is they emerge, not as the Constitution says from a deity, but from obligations of citizens to the State. Without the State there would be no rights. Indeed, his whole work is called The Philosophy of Right!
Your “everything uttered in the Constitution is sacrosanct” fingers a major problem, but there is one more fundamental having to do with its very construction. You write about speech, and it is appropriate to use it as an example of problems with this document. Amendment I is problematical, at best, “abridging the freedom of speech” if the government refers to the people having freedoms. The same Amendment I uses contradictory language in referring to “right of the people peaceably to assemble”, the question being whether “freedom” is the same as “right”. As said above, everyone in a state of nature starts out with freedoms. A “right” is what one can expect from the entity granting it, in this context a government. Obviously, here, this “right” has been abridged, as in permits often being denied certain groups.