The US Constitution stands in a long line of documents and agreements between the people of a Nation and their sovereign government, and is not an artifact of mere political compromise but rests on long standing ideas that go back to the very roots of English society, back to Engla-Land and before that to the original Anglo-Saxon invaders who would take up where Rome, in retreat, left off. Germanic and Scandinavian ways included such things as twice yearly gatherings to have the laws read and trials held, but these were trials where a jury of locals would decide a case, which was very different than the tradition of other parts of Europe and Rome at the time. A ruler or King was not separated from the law, but a part of it and the second gathering of the year was one in which complaints were heard locally and passed up to the King for hearing. From this there was not the harsh stratification of nobility as we come to know so well from the Middle Ages, for these Dark Age rulers in these conquered territories did not bring that tradition with them. From tradition comes the longest held part of how to decide law cases: jury trials by one's peers.
Through conquest and consolidation under King Alfred and his son Edgar, would arrive the spreading of the local shire governing region throughout all of the Island which had served the Anglo-Saxons so well in repulsing their cousin Danes and other Vikings. This system was put to a harsh test under King Ethelred II ('the unready') as King Sweyn of Denmark arrived for years of ravaging England after the prosperity that happened after the unification of the Island in the previous decades. When the Danes would subjugate or even come to threaten some towns or shires, they would demand payment in the thousands of pounds of precious metals. To pay off the Dane so as to be spared required annual tribute which introduced the concept of 'Danegeld' into the language. As it was said, it was easy to say that you would get rid of the Danegeld, but much harder to get rid of the Dane.
While Ethelred II had made some preparations, as the Battle of Maldon bears witness to, it came at a high price and was, in the end, a losing cause. By 1013 Ethelred and his Norman wife Emma had fled with their son Edward to the Norman held Isle of Wight which was in bad straights as it had been raided that year, as well. In early 1014 King Sweyn died and nobles of England invited back King Ethelred II to be their sovereign lord, but with some provisos attached. It turns out that a number of the nobles had been highly taxed and even had seen people in their lands taken into servitude by Ethelred, and so the resistance to the Danes might have been problematical for more than just military reasons. The overview of this agreement still can be found in The Anglo-Saxon Chronicle (which can be found at the Online Medieval and Classical Library), which had been the logbook composed by the Anglo-Saxon Kings to record in common language what had gone on in the Kingdom. King Alfred had seen this as a way of uniting peoples and its record of events gives a look into the society and happenings of the English people. The passage giving overview of the agreement from 1014 is as follows:
A.D. 1014. This year King Sweyne ended his days at Candlemas, the third day before the nones of February; and the same year Elfwy, Bishop of York, was consecrated in London, on the festival of St. Juliana. The fleet all chose Knute for king; whereupon advised all the counsellors of England, clergy and laity, that they should send after King Ethelred; saying, that no sovereign was dearer to them than their natural lord, if he would govern them better than he did before. Then sent the king hither his son Edward, with his messengers; who had orders to greet all his people, saying that he would be their faithful lord -- would better each of those things that they disliked -- and that each of the things should be forgiven which had been either done or said against him; provided they all unanimously, without treachery, turned to him. Then was full friendship established, in word and in deed and in compact, on either side. And every Danish king they proclaimed an outlaw for ever from England. Then came King Ethelred home, in Lent, to his own people; and he was gladly received by them all. Meanwhile, after the death of Sweyne, sat Knute with his army in Gainsborough until Easter; and it was agreed between him and the people of Lindsey, that they should supply him with horses, and afterwards go out all together and plunder. But King Ethelred with his full force came to Lindsey before they were ready; and they plundered and burned, and slew all the men that they could reach. Knute, the son of Sweyne, went out with his fleet (so were the wretched people deluded by him), and proceeded southward until he came to Sandwich. There he landed the hostages that were given to his father, and cut off their hands and ears and their noses. Besides all these evils, the king ordered a tribute to the army that lay at Greenwich, of 21,000 pounds. This year, on the eve of St. Michael's day, came the great sea-flood, which spread wide over this land, and ran so far up as it never did before, overwhelming many towns, and an innumerable multitude of people.
This compact is a contract between the nobles, that is those governing the shires and burrhs (later boroughs which are self-governing portions of a town) , which were the walled towns that fostered trade to make England prosperous, and their King. There are two sides in this, not just a ruler and his subjects, but a meeting of the people who are welcoming a King back if he make amends. This is a compact which is a contract to establish a sovereign leader: it is a constitution although not titled as such. What is seen is election of a leader by representatives of the people to get a fairer and more just government via clemency on both sides so as to confront an invader.
Unfortunately they were not victorious against the son of King Sweyn, Canute who would claim England as his own birthright as heir to King Sweyn. After his victory in 1016, King Canute would have the heads of the English nobility, the other heirs to the throne killed save those that were with Emma in Normandy. He would become the head of the English government, the English people and take all those places that predecessors had merely raided for tribute. He would do all of that before he was 20.
King Canute would not, however, disgrace those who fought against him and would, indeed, raise memorials to them and ensure that the line of Alfred were buried together. This was no mere bone thrown to assuage the English people as Canute would install his own people into the major sections of England but leave much of the underlying system of shires, boroughs and law-giving untouched. These sections would be given to Earls (Jarls in Danish) and this was an established system amongst the Norse dating back some centuries as a means to delegate power downwards when actual territory to rule became unwieldy in size. In 1017 he would marry Ethelred's widow, Emma, and establish the linkage between the Normans (after all the Normans were a Viking outland of Northmen) as well as legitimize his place in the royal lineage. By retaining Alfred's law system and continuing the two-way representation system that arose because of it, King Canute was becoming more than just a Danish invader conquering England: he was becoming English.
This is not as much a leap as one might expect as the Angles and Saxons had once been in that place we call Denmark today, but squeezed between the Danes and the Germanic peoples proper. Similarly the Vikings were as much about trade as about raiding and preferred the former as it was more profitable, and it was only those that resisted trade that got the blade, instead. Culturally Canute is not of very much different societal stock than the Anglo-Saxons in their Engla-land and, in some ways, by uniting with Emma he was reforging a common bond of society between these different geographic entities: sending English troops to Denmark to train, bringing the Frankified Norman customs to England and cementing that bond via marriage.
Further than that, the agreement of 1014, that one which put the status of the nobles (those lower nobility that survived, with the more powerful ones being deprived of power) into the same structure as there was with Ethelred. In other words, he agreed to his part of the contract if the rest of the nobility, not just those Danes he had put in charge, would agree to their part of it. Unlike other rulers of that era who assumed all power to themselves (indeed that would be a Frankish infusion into England), King Canute agreed to have limited powers.
The prior peace and prosperity had made England rich, extremely rich, so much so that even after all the decades of raids, the raiding of the English treasury and sending so much back to Denmark that there was still enough gold around to make a full-sized golden cross once Canute had become King in England. That is unheard of in any other region the Vikings had raided for so long, but in England there appeared to be a 'winning formula' that would bestow great wealth if the taxes could be agreeable to all.
This was important because he had so much to govern: all of England, Ireland, Normandy, Denmark, Norway, parts of Sweden. In becoming the Great Viking King, the responsibility of actually having to administer such a vast realm was daunting and to make it prosperous was essential. This means that, over time, as Earls and their families are shifted around that local nobility has a chance to establish itself in the system and to step up in ranking by demonstrating ability to govern.
What this represents is what in the US we call 'counties' under the States, with the States being similar to the multiple lands under a sovereign government. When a leader moves up from the 'county' level to the State level it is a demonstration of increased power within a given structure. Of course when the King dies, the Earls often begin to fight it out amongst themselves as these power bases over multiple shires, boroughs and towns means that they also have resources of their own: although a royal heir usually becomes King, in this early English system the King could be seen as a 'first amongst equals'. Thus the conflict that would arise between Godwin of Wessex and King Edward (Ethelred's son who becomes sole surviving to the throne) and it would pit a powerful Earl against a King seeking to consolidate his hold on the throne. In 1051 this nearly came to open civil war, save that the original compact between the nobles and the King was put into force when minor conflict in Dover between townsfolk and Godwin's people came to bloodshed, both sides were spoiling for a fight:
Then came they all to Gloucester to the aid of the king, though it was late. So unanimous were they all in defence of the king, that they would seek Godwin's army if the king desired it. But some prevented that; because it was very unwise that they should come together; for in the two armies was there almost all that was noblest in England. They therefore prevented this, that they might not leave the land at the mercy of our foes, whilst engaged in a destructive conflict betwixt ourselves. Then it was advised that they should exchange hostages between them. And they issued proclamations throughout to London, whither all the people were summoned over all this north end in Siward's earldom, and in Leofric's, and also elsewhere; and Earl Godwin was to come thither with his sons to a conference; They came as far as Southwark, and very many with them from Wessex; but his army continually diminished more and more; for they bound over to the king all the thanes that belonged to Earl Harold his son, and outlawed Earl Sweyne his other son. When therefore it could not serve his purpose to come to a conference against the king and against the army that was with him, he went in the night away.
This was a veto on the King who had a superior position. Not necessarily support of Godwin either:
There was now assembled before the king (68) Earl Siward, and Earl Leofric, and much people with them from the north: and it was told Earl Godwin and his sons, that the king and the men who were with him would take counsel against them; but they prepared themselves firmly to resist, though they were loth to proceed against their natural lord. Then advised the peers on either side, that they should abstain from all hostility: and the king gave God's peace and his full friendship to each party. Then advised the king and his council, that there should be a second time a general assembly of all the nobles in London, at the autumnal equinox: and the king ordered out an army both south and north of the Thames, the best that ever was.
When you are part of this sort of system you are limited, not just the King but each of the Earls as well. To go to war there must be agreement amongst the nobility and that nobility can stop hostilities when they hold the Nation's welfare in common above any petty factional disputes. Constitutional agreements via the compact is contractually obligating amongst the parties involved so that when one agrees to the compact is obligated by its strictures.
In 1052 there was a second instance in which Godwin was harried out to the Isle of Wight had gathered a number of ships and armed men to him and then went back to England. There were complaints to the King, as well, who then gathered ships and men and at London they met where the nobility, so key in brokering peace, no let the King know that his power had limits, as well:
On this occasion he also contrived with the burgesses that they should do almost all that he would. When he had arranged his whole expedition, then came the flood; and they soon weighed anchor, and steered through the bridge by the south side. The land-force meanwhile came above, and arranged themselves by the Strand; and they formed an angle with the ships against the north side, as if they wished to surround the king's ships. The king had also a great land- force on his side, to add to his shipmen: but they were most of them loth to fight with their own kinsmen -- for there was little else of any great importance but Englishmen on either side; and they were also unwilling that this land should be the more exposed to outlandish people, because they destroyed each other. Then it was determined that wise men should be sent between them, who should settle peace on either side. Godwin went up, and Harold his son, and their navy, as many as they then thought proper. Then advanced Bishop Stigand with God's assistance, and the wise men both within the town and without; who determined that hostages should be given on either side. And so they did. When Archbishop Robert and the Frenchmen knew that, they took horse; and went some west to Pentecost Castle, some north to Robert's castle. Archbishop Robert and Bishop Ulf, with their companions, went out at Eastgate, slaying or else maiming many young men, and betook themselves at once to Eadulf's-ness; where he put himself on board a crazy ship, and went at once over sea, leaving his pall and all Christendom here on land, as God ordained, because he had obtained an honour which God disclaimed. Then was proclaimed a general council without London; and all the earls and the best men in the land were at the council. There took up Earl Godwin his burthen, and cleared himself there before his lord King Edward, and before all the nation; proving that he was innocent of the crime laid to his charge, and to his son Harold and all his children. And the king gave the earl and his children, and all the men that were with him, his full friendship, and the full earldom, and all that he possessed before; and he gave the lady all that she had before.
Again it was the power of the Earls that defused yet another bad situation and if the actual power of England was not easy to see before all of this, it was thereafter as it was not vested solely in the King but downwards to the local organizations and places, the shires and boroughs represented by the Earls. A King could attempt to strip an Earl of his power base, his lands that he governed, but that would only be with the long-term assent of the other Earls. By rallying to one of their own, the Earls demonstrated that they were the force behind the Nation, the King their leader.
With the death of King Edward the Confessor would come years of strife between Harold and Tosty (Tostig). Harold would swear to William of Normandy that he would be heir to the throne that covered both their lands, but that was not, of necessity, a promise without limits nor one that could be reneged as it was due to unfortunate circumstances of conflict and shipwreck that put Harold in such straights. William had a direct line of succession through Emma's family and this, when bolstered by Earl Harold would allow him to exercise that claim. What had dissolved from the time of King Canute was that wider Kingdom, which was now under local rule in Denmark, Norway and Sweden once more. Claimants to the English throne now existed in these lands as well as Normandy, so that after the death of King Edward would come conflict over who was to rule England. Yet the basics that had been established on the ground prior to the 11th century, put into place at the beginning of the of it and now recognized into the 12th century remained a durable part of constitutional history, which is to say the history of all constitutional movements.
Any leader of the Nation State, which is to say the head of the government of a Nation, had limits that could be imposed upon him or her by the Nation as a whole. Thus the Nation is the foremost part of the Nation State, and the State a mere subject to it. When this is reversed, when the State is made primary, there is tyrannical rule, barbaric rule, rule by force of will and whimsy of the rulers. Rulers who wish to have all power of the Nation to them respect no continuity of government or governing, there is no assurance of regularity of trials nor of the legal process. If any ruler were to set such limits, write them down and agree to them, the question would be: who would be on the other side of the table to accept the agreement? The very recognition that there needs to be regularity of government is a recognition that man is mortal while a Nation is durable beyond any single ruler or ruling oligarchy. Any oligarchy, in fact, is a distribution of power to more local levels for no matter how centralized the ruling contingent, those in an oligarchy represent smaller parts of a Nation. This can serve as the beginnings of a constitutionally limited system as those in an oligarchy will tend to see, as the Earls of England, that the ruler was a first amongst equals.
In the US the design of the Constitution is one that safeguards the power of the States and the people against the government of the Nation State. National power is directly stated in the Preamble as resting with the people, not the government, and that the government is granted sovereign power by the consent of the governed. This is the party of the first part, the people, telling what the terms of government are to those willing to take up the work of being the party of the second part, the government of the Nation's State. Thus the veto over such power rests not in the government but, as it was in the time of Ethelred II, in the signatory parties: the States and the ultimate power now asserted directly the people who are the ones that make the Nation.
From a few lines of an agreement done centuries ago, the outlines of what powers any State can have are laid out. What had been a rough and ready understanding of what drives Nations and what their powers were under law of nations, was becoming something beaten out during the people who were the Nation and those who would wish to govern it. Those wishing to undo this are not civilized nor putting forward the cause of knowledge and understanding of why the power of the State must be limited.