Nine elected positions hang in the balance when Cobb County voters hit the polls Tuesday.

There are 20 municipal races across five cities on this year’s ballot. Eleven of those races feature candidates who will go unchallenged, including nine incumbents.

Marietta, the county seat and Cobb’s oldest city, will be the biggest battleground. It’ll represent the lone municipality in Cobb with a contested mayoral race.

Michelle Cooper Kelly is leaving her seat as 6th ward councilwoman in an effort to become Marietta’s first Black mayor. She’ll have her hands full, facing three-term incumbent Steve “Thunder” Tumlin, who was first elected mayor in 2009.

Cooper, who is finishing up her second term as councilwoman, is running on a platform of more jobs and workforce housing, more officers on the police force, and tapping into the city’s shifting demographics of young professionals.

Tumlin has touted strides the city made under his leadership like creating the Gateway Marietta CID in 2014 and $25 million worth of improvements to the city’s parks. He’s emphasizing safer streets, reinvestments into Franklin Road and the busy Marietta Square, and support for the Marietta City Schools system.

Each of the city’s seven council seats are also up for re-election. Three of them are unchallenged races.

Councilman Reginald Copeland will have to knock off two realtors — Cristina Stallworth and Carlyle Kent — to retain his Ward 5 seat.

In Ward 2, incumbent Griffin Chalfant will be challenged by restaurant owner John Silvey. Write-in candidate Catrina Barr faces off against Councilman Johnny Walker in Ward 3, and Ward 4 Councilman Andy Morris will have to battle art designer Ted Ferreira.

In Acworth, Mayor Tommy Allegood is unopposed for his sixth term.

In Powder Springs, where new development is at the forefront on many voters’ minds, Nancy Farmer is the only incumbent with a challenger on the ballot. She will face Dwayne Green, a funeral home owner, for her Ward 4 council seat.

Former Kennesaw councilman David Blinkhorn vacated his Post 5 seat to run in the State House Representative District 34 special election earlier this year. Real estate broker Jon Brothers battles Trey Sinclair, owner of downtown brewery Dry County Brewing for that spot.

Ballots will include a referendum for a new 1% education special local option sales tax, or E-SPLOST, to fund capital improvements for Cobb County and the City of Marietta school districts. The current E-SPLOST penny tax expires Dec. 31, 2023. The ballot initiative, if approved by voters, will extend it another five years.

No seats in are up for election in Smyrna or on the Cobb County Board of Commissioners.

Four-year terms of office that begin Jan. 1 are at stake in each municipal race. Any runoffs will be held on Nov. 30.

By Tuesday, nearly 8,000 voters had cast early or absentee ballots in Cobb, according to statistics provided by the county’s Election & Registration office.