Ah, but therein lies the rub: you've decided "the basic functions of government" - not what you believe should be the basic functions, or the allowable limits, but what they are.
I haven't
decided jack. I merely said that there are some basic functions of government that are difficult or impossible to "opt out of" when they exist. Education is not one of them, unless we make laws forbidding private education.
I didn't discuss what they should be, or how they should be limited. I simply gave examples of basic functions that can't easily be "opted out" of. You're on a tangent here.
The state, unions, labor unions, the Klan, trial lawyers' advocacy groups, etc. are organizations of people. They are not treated, themselves, as individuals under the law.
Corporations are.
That whole statement is part true, part false.
Corporations have many special rules that only apply to them, not to individuals. So while corporations are "individuals" in one legal sense, they are not equivalent in the law, not by a long shot. I'm not saying this is good or bad, just that you don't present a complete picture.
Furthermore, there are also special rules that apply to unions, trade unions, etc. that give them power over and above an assembly of people. Sometimes, that power includes the legal ability to decide who can work in a certain field, sometimes it includes the legal ability to force people to join and pay dues. Some such groups have quasi-governmental powers, with little accountability. Individuals would be guilty of serious criminal charges if they did some things done by trade unions, labor unions, and the like. This may or may not be appropriate, but many groups that aren't "corporations" as you use the term have legally-bestowed power that goes beyond the cumulative power of the members.
So, yours is a false dichotomy here. I think there are problems with all of the above, and then some. However, it's not the simple "corporations vs. every other group and individual" scenario you make it out to be.
The Constitution is all well and good, if for no other reason than it is legally and politically useful for all people to have a basic document from which everything else can be derived. It is not the flawless, quasi-religious document that it often seems to be treated as.
Nope it isn't. We seem to have forgotten the idea of the Amendment, and instead we have contrasting theologies arguing over scriptural interpretation. I think that is bad, also.
Only if you decide that education has no societal benefit (which, frankly, would be laughable - we can see the benefits of education in income, criminality, family health, healthcare, economic impact, etc.).
It would indeed be laughable to say it has NO societal benefit. Therefore, your argument is meaningless. Every positive thing has a societal benefit. Sometimes, it comes with a cost, as well.
For example, we all benefit from a thriving economy. If we all decided to sleep in, get stoned, and blow off work for a few months, we would all suffer. Those few who chose to continue working might suffer the most, because without much of a GDP, they would have no more food, clothing or shelter than anyone else in the economy.
HOWEVER, if you argue that it is morally justifiable to force people to do whatever has a benefit to society at large, then it would be morally justifiable to send the military to get everyone out of bed and force them to their offices at gunpoint. Productivity has a societal benefit. If need be, we could put people into work camps if the refused to work for the good of society.
I doubt you'd buy that.
So the fact that something is good for the rest of us doesn't automatically make forcing it on people moral. Sometimes it is, sometimes it isn't. Few if any people object to imprisoning murderers, for example. The decision will have to be made based on other criteria, though.
Now, do I actually believe that one should be allowed to opt out of taxation that may in some part pay for things one finds objectionable (even morally objectionable)? Of course not, that's tantamount to funding the state through donations. A fine idea in theory, never gonna happen in reality. We elect people to bargain for us - that's our democratic system. And we work within that system to get them to do the right thing whenever possible.
We don't have a democratic system. We have a constitutional republic. That is intended to apply more checks and balances that encourage "them to do the right thing whenever possible." Furthermore, a smaller government, at worst, does fewer wrong things.
Of course, none of this necessarily supports public education.
Maybe public education is the "right thing," maybe it's not. That, too, would need to be decided based on other criteria than just "it has some benefit" without regard to costs, and the slogans of bumperstickers.
Those who want to examine that system are doing exactly what you prescribe: "work within that system to get them to do the right thing whenever possible." The fact that they don't share your assumptions about public schools doesn't negate that in any way.
