Eugene Volokh questions my observation that a “right” existing at the sufferance of the state is largely illusory. He notes, correctly, that rights (i.e., legal entitlements) can be held against parties other than the state, in which case such rights are genuine indeed. Suppose, for example, that you and I were to enter into a contract, which the California Legislature could nullify by statute at any time. My rights against you, and your rights against me, would both exist at the sufferance of the state, but neither of them would be illusory (assuming, of course, that neither of us has enough political clout to force the Legislature’s hand). If, on the other hand, the contract contained a clause allowing one of the parties
to rescind the contract at any time, the other party’s contractual rights would be illusory indeed. Thus, my original statement probably should have been worded a little more generically:

To the extent that a “right” exists only at the sufferance of the person against whom it is asserted, it scarcely deserves to be called a “right” at all.

That said, I do believe the original quote works in context. People who repeat the DMV mantra that “Driving Is A Privilege Not A Right” are asserting a right of the state, not of private individuals, to curtail the citizenry’s driving rights/privileges. Thus, in this instance, a “right” existing at the sufferance of the state as illusory as anyone’s contractual duty to “perform X if I want to.”

None of this is intended to suggest that a right has to be grounded in the federal (or state) Constitution to be a bona fide “right” against the state. Even a purely statutory right is enforceable against those segments of the state that lack lawmaking power, such as the DMV. As to the state as a whole, however, I don’t think it makes much sense to describe driving as a “right” solely because the 50% + 1 of the Legislators have not yet exercised their right to revoke it. For the word to mean anything of substance beyond that which is also implicit in a “privilege,” severe burdens on driving ought to be at least slighly harder to pass than ordinary legislation, e.g., require a supermajority vote, if they are not prohibited by a separate body of law which the state cannot change at all. A federal “Right to Drive Act” would probably put the debate to rest just as thoroughly as a constitutional amendment would, although there is also a possibilty that such a law would merely shift the focus of the debate to the federal level.