“I confess that I do not entirely approve this Constitution at present, but Sir, I am not sure I shall never approve it. . . . In these sentiments, Sir, I agree to this Constitution, with all its Faults, if they are such; because I think a General Government is necessary for us. . . . . I doubt too whether any other Convention we can obtain, may be able to make a better Constitution. . . . . It therefore astonishes me, Sir, to find this System approaching so near to Perfection as it does; and I think it will astonish our Enemies, who are waiting with confidence to hear how our Councils are Confounded, like those of the Builders of Babel, and that our States are on the Point of Separation, only to meet, hereafter, for the purposes of cutting one another's throats. Thus I consent, Sir, to this Constitution because I expect no better, and I am not sure that it is not the best. . . . . On the whole, Sir, I cannot help expressing a Wish, that every Member of the Convention, who may still have Objections to it, would with me on this Occasion doubt a little of his own Infallibility, and to make manifest our Unanimity, put his Name to this instrument.” -- Ben F., 1787
In significant part, (1) the disagreements the drafters of the Constitution including its Amendments struggled with were not resolved, and (2) we are today deeply, bitterly divided over modern variants of many of those same disagreements. It is impossible for humans to agree on what the words of the constitution meant. Literally impossible. It cannot be done.
The drafters used "strategic ambiguity" as a means to get the constitution drafted, agreed upon and then ratified. Strategic ambiguity was needed to deal with intractable special interest demands and faction or ideological demands. Regarding contested concepts, when people disagree about whether "liberty" protects economic freedom or reproductive autonomy, they're not merely confused or biased. They're operating from different normative mental frameworks about what human flourishing requires or about what is best for themselves and/or others.
That is value pluralism, i.e., recognition that fundamental values can genuinely conflict without rational resolution. It's not relativism (all views equally valid) or nihilism (no views defensible), but rather the acknowledgment that moral disagreement can be rationally irresolvable because people start from different, internally coherent moral and social values. Constitutional meaning is contested not just because people are biased, confused or ignorant, but because the constitutional text employs normatively loaded concepts about which reasonable people fundamentally disagree.
That is mostly why it is impossible for people to agree about what some significant parts of the Constitution say.[1] The Constitution is necessarily ambiguous and therefore cannot be authoritatively interpreted. Political factions interpret what it means through the lens of humans being human and ideology being what it is.