MEMPHIS, Tenn. (AP) — Voters in Tennessee's largest county will decide Thursday whether a state Senator or a county Trustee will be their mayor for the next four years.

In Shelby County, Republican David Lenoir and Democrat Lee Harris are vying to replace Mark Luttrell, a two-term Republican mayor who cannot run again because of term limits. The winner will preside over a county with a population of about 930,000 in West Tennessee.

Shelby County includes the city of Memphis, which elects its own mayor but also falls under the purview of the county mayor. Memphis' current mayor is Jim Strickland.

Both Harris and Lenoir have name recognition. Harris is a University of Memphis law professor and a former Memphis City Council member. He served as the Senate Minority Leader in the General Assembly and has been outspoken on several issues, including his support of the removal of three statues of Confederate leaders from public parks in Memphis.

Lenoir played football at the University of Alabama and then worked in the financial services industry before he was elected to serve as the county Trustee — also known as the county's banker — in 2010. His name appears on property tax bills sent to Shelby County homeowners.

The race has been contentious at times. Lenoir has claimed Harris is weak on crime, and Harris has said Lenoir has been part of a political establishment that lacks energy.

Voters could make their decisions along racial lines. Lenoir is white, Harris is black.

Experts say voter turnout is a key factor in the election. Turnout is typically lower in election years when there is no presidential race. Suburban white voters in the county typically have a good turnout — a fact that benefits Lenoir — so a strong showing from voters in the majority-black city of Memphis would help Harris, said Marcus Pohlmann, a political science professor at Rhodes College.

"There's a lot of Democratic intensity across the board and across the country it seems, and whether that will be reflected in a larger than normal city Democratic vote remains to be seen," Pohlmann said Monday.

Election data shows that about 15 percent of voters went to the polls for early voting.

"I had hoped for more but it is a primary, so frequently people wait until Election Day to vote," Linda Phillips, the county's elections administrator, said in an email.

Meanwhile, across the state in East Tennessee, voters in Knox County will also be choosing their next mayor. The race in the solidly Republican county pits GOP candidate Glenn Jacobs, a small business owner and former WWE wrestler known as Kane, against Democrat Linda Haney, who ran small businesses with her husband before she retired.