After California became a U.S. state in 1850, its Legislature grappled with how state and local governments would be structured. One decree was that counties, beginning with Los Angeles, would have five-member boards of supervisors.

Almost everything about California’s governance has changed in the last 175 years — even the size of its Legislature, which an 1879 constitutional amendment set at 80 members in the Assembly and 40 in the Senate.

With one exception, the city and county of San Francisco, California’s counties have had five-member governing boards ever since, including tiny Alpine County, with scarcely 1,000 residents, and Los Angeles, with nearly 10 million.

That’s going to change. Last year, after decades of unsuccessful efforts to overhaul how Los Angeles County is governed, a minor miracle occurred when its voters approved an expansion of its Board of Supervisors to nine members after the 2030 census. It was miraculous not only that it occurred but that the reform was proposed by the current board itself — albeit not unanimously — in a remarkable display of willingness to dilute members’ powers.

Even more stunningly, the ballot measure also made a quantum reduction in the board’s powers by creating the elective office of county executive with potentially sweeping authority to govern the county, much as California’s governor or a big city mayor does.

Given Los Angeles County’s immense population exceeds all but 10 states, as well as its outsized economic, cultural and political weight, the ballot measure instantly created a position that would be second in real-world power only to the governorship. The occupant would automatically become a potential governor or U.S. senator.

The exact extent of the county executive’s authority, however, was not spelled out in the ballot measure. Instead, Measure G created a 13-member Governance Reform Task Force that will recommend the details of implementing its provisions, including the county executive’s authority.

The task force, reflecting the county’s extremely diverse economic, cultural and political communities, held its first meeting last week and the executive’s powers were a preoccupation of its members, some of whom opposed Measure G.

As the Los Angeles Times’ account of the meeting put it, “Should the chief executive be able to hire and fire department heads? What are the veto powers? How much control will the executive have over the county’s purse strings?”

The Times quoted Marcel Rodarte, a task force member who heads the California Contract Cities Association, as worrying about a bombastic executive “running amok and burning bridges unnecessarily,” adding, “It’s a possibility it could happen. I want to make sure that those nine supervisors have the ability to rein in the CEO.”

Rodarte’s members, which comprise dozens of small Los Angeles cities, contract with the county for such things as police patrols and fire protection, so they are concerned about who will be sitting across the table in contract negotiations. County employee unions expressed similar reservations about labor contracts.

One of the big questions is whether the county executive will have a term limit.

Governors, legislators and other state officeholders have term limits. Gov. Gavin Newsom’s second term will end in 19 months and has publicly cited the impending end of his governorship in seeking action on his priority issues.

As it stands, the county executive will not be term-limited, and that potentially looms large in the task force’s recommendations for amending the county charter.

There’s not a lot of room for protracted debates among task force members because the first county executive will be elected in 2028. Every ambitious Los Angeles politician will be weighing a campaign and everyone needs to know what the winner can — and cannot — do after being inaugurated.

Dan Walters is one of most decorated and widely syndicated columnists in California history, authoring a column four times a week that offers his view and analysis of the state’s political, economic,...