It's true, of course. Everyone does have the right to formulate and express an opinion of his choosing. What I hate about the phrase is that it implies that opinions are equally devised and should be measured as such.

It is an embodiment of the premise of Jonah Goldberg's fantastic book, A Tyranny of Clichés: How Liberals Cheat in the War of Ideas, though I don't believe it's one of the many he tackles. It's a pseudo-argument that's not actually an argument – offered as pithy wisdom but serving no purpose other than shutting down further discussion about the substance being discussed.

A person's specific opinion is justified or valuable not simply because he has one. Opinions are not equal, nor should they appraised that way.

To illustrate my point, imagine that you sit at one side of a table. You tell the man sitting on the other side that you want nothing from him, and that you simply want to be left alone to do what you will, none of which is in violation of any existing laws. You tell him you pay tribute to the communal coffers as prescribed by law, though you disagree as to why such substantial tribute is required, and you have reservations about the efficiency and intentions of the growing body of bureaucrats at the shadowy end of the table who appropriate and dole out your wealth to others, and to the various offices of their creation that finance things that you do not agree with.

On the other side of the table, the man tells you you actually have too much wealth, while he has too little. He tells you you actually pay far too in little tribute, and you should be paying far more. He says the growing body of bureaucrats at the remote end of the table should be charged to take more from you (though not from him) so he might have more money and the distribution of wealth might be made "fairer" for those who have less, and to finance all the things he wants to have done with your money.

You and the other man each have an opinion, and you were free to express it. But are the opposite positions of the two men in the above example "equal"? If not, who has the stronger position?

Without hesitation, I say you have the stronger position, morally and reasonably. You are not asking anything of the other man and are interested simply in retaining more of your own property because you are concerned about the ways that your wealth is directed by the bureaucrats who seem to care little about your desires.

The other man simply wants more of what you have for him and others like him.

A leftist might see it differently.

A democratic purist might say that the salient facts needed to answer that question are how many people sit behind each of the two men at this table to bolster either's position through a popular vote, which would determine who was correct. If the other man has more people behind him, then he is correct.

A Marxist might say that because the man has less money than you, it is required that more be forcibly taken from you to provide an equitable distribution of means, therefore the other man is correct.

In an open marketplace of ideas among reasonable people, would either the democratic purist or the Marxist have a convincing argument?

I'm not blind to the fact that there may be more people who stand to benefit from the redistribution, and they might be swayed by that fact rather than appropriately and reasonably consider the issue. But truth be told, neither the democratic purist nor the Marxist cares about your liberty. And individual liberty, though a moral concept, is central to our American identity. The democratic purist allows morality to be shaped by popular opinion, while the Marxist owns a dark and twisted sense of morality entirely antithetical to the very concept of liberty. In both cases, their "opinions" are a direct subversion of your liberty that they hope becomes manifest via the confiscation and redistribution of your wealth.

Again, you're asking nothing of them. You are only asking that you be able to keep more of what is yours.

The protection of individual liberty is the core purpose of American government, built into our nation's framework. As I've aged, I've come to believe that this is the fundamental distinction that separates the American idea from the rest of the world. And I've come to understand that to destroy our notion of individual liberty requires the institution of this silly notion of moral relativism, where your opinion and mine are equal simply because we have opinions and a vote.

Offer an analogy like the one I offered above to folks of a leftist persuasion. Tell them that your opinion does not require that others have their wealth sluiced by government bureaucracy, but that leftists' opinions require that your wealth be taken from you to provide for things you do not condone. See what they say. I'd wager that they'll do what they likely always do when challenged by ideas they cannot combat on the grounds of reason. Your ideas, though they would likely be found superior in any free discussion, will quickly be relegated to the realm of "Well, that's just your opinion, man. Everyone's got one."

William Sullivan blogs at Political Palaver and can be followed on Twitter.