THE RAPID POLICY reversal at Santee Cooper after Gov. Mark Sanford fired the board chairman offers an important reminder about the difference between theory and practice in state government.

Under a little-known and less-utilized provision of the 1993 government restructuring law that gave the governor direct control of a handful of major state agencies, governors can dismiss the members of the boards and commissions that run most other agencies.

Within days after Mr. Sanford removed the chairman, with whom he has repeatedly clashed, the board slashed charitable donations by the quasi-independent state-owned electric utility — something the governor had been advocating for more than a year.

That was precisely the type of responsiveness lawmakers said they were allowing when they offered up this power as an alternative to giving the governor direct control of all agencies. A governor who could dismiss the members of boards that run agencies had the implicit power to control those agencies, they argued.

That’s true in theory. But practice is different, as is obvious from the fact that Mr. Sanford is the fourth governor to have that power and the first to use it in a way that clearly was directed at changing policy, and not simply rewarding friends and punishing foes.

The underuse of the power probably doesn’t trouble those who prefer that state agencies ranging from the Department of Mental Health and the Commission on the Blind to the State Museum and S.C. ETV be controlled largely by little-known individuals who aren’t elected by the public and aren’t accountable to anyone.

It should, because when the governor can pretend he has no authority over state agencies, he can also avoid taking responsibility for what happens at those agencies. That means he isn’t accountable — and so nothing happens — when things go horribly wrong and immediate action is needed.

More often, it means he isn’t spending enough time thinking about how to make sure these agencies work as they should. This has been illustrated by Mr. Sanford’s response to budget shortfalls at critical state agencies. The governor has been a vocal advocate of additional funding at the Department of Corrections, which is in his Cabinet. But he has had little to say about the equally underfunded Department of Mental Health, which is run by a board whose members he can hire and fire at will. So that agency has not had the high-profile advocate it needs as it has been forced to cut services to the dangerously mentally ill.

Governors have been reticent to take ownership of board-run agencies because there are so many of them, and each has so many commissioners; a governor could easily spend all of his time making the appointments that will move the agencies as he prefers.

That means that although an elected official is technically empowered to control most agencies, it is practically impossible for him to do so. And it means that even when the power is used, it is terribly random. This scattershot approach at accountability allows governors to cherry-pick those agencies that interest them, as Mr. Sanford has done, while ignoring agencies that are far more central to the duties of state government.

It is inexcusable that lawmakers have refused at least to consolidate the executive branch into a reasonable number of agencies — say, 20, instead of more than 100. If they did that, governors still would have to jump through hoops to exert control, but at least it would be physically possible.