The Pima County Superior Court, left, the Pima County administration buildings in Tucson.

 A.E. Araiza / Arizona Daily Star

PHOENIX — Residents of the state’s two largest counties could find themselves with more people to call when something goes wrong.

But it will cost them.

On a 15-13 margin the Arizona Senate on Tuesday gave preliminary approval to expanding the size of the Maricopa County Board of Supervisors from five to nine. SB 1498 also would increase the size of the Pima board from five to seven members.

The move came over the objection of several Democratic lawmakers who said the board members in the two affected counties are opposed. Sen. Victoria Steele of Tucson said the issue for the supervisors in her county is cost, at least in part.

The cost of operating an office, including salaries and equipment, is about $500,000. So two new supervisors in Pima County would increase public spending by $1 million, what she called an “unfunded mandate.”

Sen. Lela Alston, D-Phoenix, said there were similar objections from the Maricopa supervisors.

But Sen. J.D. Mesnard, R-Chandler, said the two counties have grown so large that individual supervisors can no longer adequately represent their constituents.

He said the situation is particularly pronounced in Maricopa County where each of the five supervisors represents close to 900,000 residents. Adding four more board members would cut that to about 635,000 per district.

It’s not quite as severe in Pima County where a supervisory district now consists of about 200,000 residents. Going to seven would cut that to about 150,000.

Still, Mesnard defended extending his legislation to Pima County. He said it’s a “similar principle though obviously not as extreme.”

The idea of linking the number of supervisors to population is not new.

Arizona law already says that once a county hits 175,000 the size of the board has to go from three to five.

Mesnard’s bill simply adds two new thresholds.

At a million, the minimum becomes seven. And at three million, that requires nine.

“There comes a point in time when trying to represent a very large number of people is difficult,” Mesnard said. In fact, he said, at 900,000 the size of Maricopa County districts is larger than any of the state’s congressional districts.

Steele does not dispute that number.

But she said that most county residents actually live within the incorporated limits of a city.

In Pima County, the most recent estimates show 35% of the population is in an unincorporated area. It’s even more pronounced in Maricopa County where just 7% of residents do not live within a city.

And Steele said that means they are more likely to call a council member with a problem than a supervisor.

Mesnard said that may be true but it does not make them any less important.

“They’re still elected officials who have a constituency,” he said. “I am a believer in the idea that the smaller the constituency that you represent, the more tailored, the more focused, the better representation you get.”

Mesnard said that it is “absolutely true” that a government can be more efficient when there are fewer people in charge. But he said that does not tell the whole story.

“They would be very efficient having single persons governing everything,” Mesnard said. “But we all know that’s not a good principle.”

The measure still needs a final roll-call vote in the Senate before going to the House.

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