Hillsborough County commissioners must draw nine new district boundaries by Oct. 1, 2027, after voters approved expanding the board and eliminating countywide seats.

The restructuring will cost between $1.9 million and $2.3 million in its first full fiscal year, according to a legislative fiscal analysis of the bill that placed the referendum on the ballot. That estimate drops to $1.1 million in the second year. The Hillsborough County Supervisor of Elections also faces a one-time $740,000 expense to send updated voter information cards.

The charter amendment, House Bill 4029, was sponsored by Apollo Beach Republican Rep. Michael Owen, a former county commissioner. Owen argued before the vote that countywide elections concentrate power in the city of Tampa and dilute the influence of suburban voters, WUSF reported Oct. 30.

Voters approved the measure Nov. 3 with 253,488 votes in favor and 236,601 against, according to unofficial results reported by Florida Politics. That 52% margin replaces the county's mix of four district seats and three countywide seats with nine single-member districts, effective with the 2028 general election. All nine seats will be on the 2028 ballot, with staggered two- and four-year terms.

Former Hillsborough County Commission Chairman Les Miller said he pushed for the expansion years ago but was turned down repeatedly, according to Bay News 9.

"I brought it to the county commissioner, I think on three different times. Three times they shot me down," Miller said.

Miller said the new structure will make commissioners more accountable. "You vote for one, but that one person answers to you," he said. Each district must have nearly equal population, with a 5% differential allowed, according to Miller.

Not everyone sees a clean win. Former Hillsborough County Commissioner Rev. Thomas Scott said he preferred a mix of at-large and single-member seats.

"My view would have been a four or five for at-large and five single-member districts," Scott said. "I thought that would have been a better representation versus nine single-member districts."

Scott said the change could reduce voters' influence on countywide issues because they will vote for fewer commissioners. Under the old structure, residents voted for one district commissioner and three countywide members. Under the new system, each voter picks one. Scott added that long-term costs could grow because commissioners receive benefits including health insurance and retirement.

The restructuring also raises the bar for key county decisions. Appointing or removing the county administrator, county attorney and internal auditor will require a "majority plus one" vote of the full commission. The same threshold applies to proposing charter amendments.

Democrats will oversee the boundary-drawing process after winning all four commission races Nov. 3, flipping the board from a 5-2 Republican majority to a 4-3 Democratic majority, Florida Politics reported.

Hillsborough County adopted its current charter in 1983. The county's population has more than doubled since then, reaching approximately 1,581,426 residents as of July 2024, according to the bill analysis. If the population hits 2.5 million based on a future federal census, the board would expand again to 11 members.