The court's ruling, which would have the company open the purse-string of its app store, is not a matter of mere commercial inconvenience. It is the same contest, in a new costume, against the unchecked concentration of private power — a contest as old as the Republic, and as necessary.

I have, in seasons past, opposed those who would bind the energies of inventive people by too rigid a hand. The engineer who improves a process, the merchant who finds a route, the founder who refines a method — each deserves the fruit of her industry. To deny that is to deny the cause of improvement itself, on which a free people depend.

But the present case is not so simple. The instrument in question is not a single shop, nor even a single industry. It is one of the few gates by which a great mass of modern commerce now passes. A toll levied at such a gate, set by a single house and answerable to no rival, is in substance a tax — and a tax laid by a private authority upon a public traffic is precisely the danger our compact was meant to guard against.

We are told the company has built this gate at its own cost, and so may charge as it sees fit. The argument has merit, and would carry weight in a smaller matter. But the test, when private power approaches the public, has always been: can the citizen, finding the toll oppressive, turn aside to another road? When she cannot — when the gate is, in effect, the only gate — then it has ceased to be a private concern.

It is sometimes urged that to interfere is to punish success. I would answer that to refuse to interfere is to permit success to become sovereignty. The merchant who, by his merits, has gathered so large a share of the commerce that he sets its terms is no longer a merchant only; he is, in that province, a legislator. The proper response is not to break him for his merit, but to ensure that the commerce passes through more than one set of hands.

A republic must guard against the unchecked concentration of any private power, however ingenious its inventions, and must do so not in spite of its love of enterprise but precisely because of it. The court's order may chafe at the company; it does not chafe at liberty. It restores a balance liberty requires.