On closer examination, we can probably agree on more than just the list of general purposes. We can probably agree that a government charged with establishing justice, ensuring domestic tranquility and promoting the general welfare of 1000 people has a more difficult task than a government charged with the same responsibilities for a population of 100 people. These tasks, in particular, and perhaps the others as well, are pretty clearly tasks that require a bigger government for a larger population than for a smaller population. These three purposes of our government, at least, involve mediating the interactions between citizens, especially when those interactions involve conflict. As the number of people in a society increases, or more accurately, as the effective population density increases, we might expect the number of interactions requiring government mediation to increase as well. We can use effective population density as a yardstick to approximate, at least on a relative basis, how much government is required to achieve the purposes identified by our Constitution.
Effective population density captures the idea that, as you increase the number of people in a given area, and increase the technology with which they can affect the people around them, you will increase the number of interactions that are likely to require some kind of government regulation or intervention. Basically, if the Hatfields and McCoys want to go off in the middle of nowhere and have a feud that doesn't affect anyone around them, some might say that is their business. But move that feud to downtown Manhattan at rush hour, and we can probably agree that the government has an interest--a duty even--to intervene, mediate, regulate, control or prevent the feud. To properly "establish Justice, insure domestic Tranquility,... [and] promote the general Welfare" of all the innocent bystanders who would be hurt by the fight in downtown Manhattan, we can probably all agree the government has a duty under our Constitution to intervene.
In the era of the founding of the United States of America (1775-1788) it took 7-10 days to travel the 308 miles from Lexington and Concord to Philadelphia, depending on whether you rode a horse or rode in a carriage. Let’s take the low end of that range: 7 days is 168 hours. So the speed of information was roughly 2 mph. There were about 3 million colonists and slaves living in the original states, which controlled at most an area of about 200,000 square miles, for an average population density of roughly 15 people per square mile. We might assign a "technology factor" to account for the fact that, in a given space, the ability of one person to affect or communicate with other people was limited by the range of their voice, or, if they were fortunate enough to know how to read and write, by their access to a book or newspaper. Even the effective range of common weapons was limited to a fraction of a mile, and their rate of fire, for an expert, was 2 to 3 rounds per minute. But there were newspapers, and according to the census of 1790 we can estimate that about 5 percent of the population lived in cities. So let's arbitrarily assign a technology factor of 5. Given all this, then, we might calculate the effective population density to be 2 miles per hour times 15 people per square mile times a technology factor of 5 for an effective population density of about 150.
Today, in the United States, we have about 330 million people living on 3.8 million square miles, or roughly 87 people per square mile. Today, information travels at the speed of light: roughly 671 million mph. Multiplying those numbers together, even with the simplifying assumption that the technology factor is part of the increase in the speed of information, yields a staggering 58 trillion. On this view, the effective population density of the United States today is nearly 400 million times what it was in 1790.
This number is probably way too big. After all, the combined speed-of-information-and-technology factor in the second calculation masks the fact that, as the cost of communicating with each other has gone down and the frequency has gone up, the significance of many individual transactions has also lessened. Not every email can be equated to a Hatfield-McCoy feud in its impact on justice, domestic tranquility, and the general welfare. But even with other reasonable, if arbitrary, reductions, the fact remains that modern society is exponentially more complex than the society the framers of our Constitution experienced.
The quality and quantity of changes between their society and ours are so great that the men who wrote and ratified the Constitution could not have imagined all the things that would be necessary today to achieve the purposes they enumerated for our government. They could not have imagined, for instance, e-commerce and air traffic safety and cyber crime. But they gave us the six purposes they thought any government of free people should aim to accomplish: "to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity." As I see it, that all basically boils down to regulating interactions between people within our society and with people in other countries in such a way as to keep us all from having to go to war with each other to secure our basic rights.
People who complain that government is too big or is too involved in our daily lives should offer a blueprint for how, exactly, government is supposed to "form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity" in today's society without being more involved in our daily lives than it was in the days before electricity. If the purposes of government are to regulate interactions between people to remove the need for those people to resort to the Hatfield-and-McCoy type of solution, then I think the government should be big enough to accomplish that purpose. And I think that, when it comes time to elect people to serve in our government, or to decide whether to support some new idea, we should consider our choices in the context of the purposes of government as identified in our Constitution.
The power of this approach is that it provides a simple, shared framework for discussion and argument that is independent of your political party, your religion, or the color of your skin. Using the framework will not answer every question or solve all of our disagreements, but it will allow us to focus on whether or not some proposed law is a legitimate exercise of governmental power. Because frankly, there is nothing in the Constitution that says I have to agree with your ideas on religion, or your political philosophy, or your ideas on how to improve society. In fact, the Constitution gives me the express right to disagree with you and everyone else on all of those things. We are more likely to achieve meaningful outcomes if we use the framework provided in the Constitution to focus our discussions about what government should do on any particular issue than if we waste time on matters where we are all entitled to our own opinion.
The beauty and power of the United States Constitution is not that it contains a tailor-made solution for every new type of problem that has emerged over the past 230 years. Rather, the beauty of our Constitution is that it contains a framework for tapping the wisdom of each generation to solve that generation's problems. The beauty of the Constitution is that it recognizes one thing does not change--people continue to disagree over how to use the resources of our society to solve the problems we face. The beauty of our Constitution is that it includes fair processes for considering opposing viewpoints as we try to resolve our disagreements. The proper use of our Constitution is not to suppress dissent or to take us backwards to some imagined "good old days." The magic of our Constitution is its power to use reason to leverage our differences, with all parties making the best case possible for how their programs, proposals and candidates can help us "form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity".