SINCE THE TURN of this century, Montgomery County has exceeded state education funding guidelines, which set minimum per-pupil expenditures, by about half a billion dollars. That extraordinary commitment has helped make the county school system a national model.

Thanks to a radical rewrite of state laws driven by special interests in Annapolis, Montgomery is unlikely to do more than the minimum ever again.

As we wrote recently, state lawmakers are in the process of a sweeping and unwise overhaul of the way schools are funded. The intent is sound: to ensure that counties do not slack off as the state boosts its own school funding. But in the case of Montgomery, the state’s largest system, the effects could be extremely damaging.

The legislation would empower the state to claim local income-tax revenues and redirect them to schools if counties were deemed to have fallen behind on the education funding requirements. It allows for no flexibility — even during recessions, when every other agency of local government is slashed.

Since 90 percent of local education spending goes to personnel, it all but ensures that salaries and benefits for teachers, janitors and other school employees would hold steady or grow, even if thousands of other public employees made deeper sacrifices, as many have in recent years.

The measure, pushed hard by Sen. Richard S. Madaleno Jr. (D-Montgomery) and other lawmakers, as well as by teachers unions, injects steroids into the state’s “maintenance of effort” law. In Montgomery, some are referring to it as a “maintenance of salary” law. And with good reason.

It would neither credit the county with exceeding state minimums in the past, nor allow any realistic wiggle room in the future. The effect, Montgomery officials say, is to guarantee that the county will never again exceed funding minimums, for fear of locking in unaffordable levels.

The legislation could force sharply higher local taxes, even if it meant ignoring voter-approved local tax caps. It could also divert tax dollars away from police, fire, health, libraries, parks, recreation centers and other priorities. In Montgomery, schools already account for a little more than half of the county’s $4 billion in tax-supported spending.

Moreover, since cutting local education budgets in any way would violate state law, another effect of the law could be to enshrine bloat, waste and even fraud in school budgets. Talk about perverse incentives.

Simultaneously, the legislature is moving toward passage of another bill that would stick county councils with half the bill for teachers’ pensions, even though the salaries on which those pensions are based are set by local school boards.

Taken together, the legislation would strip elected county officials of any real say over the half of their budgets devoted to education, and shift real authority to set pay, pensions and benefits to teachers unions, who already enjoy virtually unchecked power in Maryland government. The losers would be voters and taxpayers, who would be stripped of influence and a voice in determining how their money is spent.