Alabama is gearing up for another election season.

Alabamians, and residents from 13 other states, will head to the polls next week to vote in the Democratic presidential primary. In Alabama, there will also be a Republican primary for U.S. Senate. Alabama Sec. of State John Merrill expects 1.1 to 1.3 million people to take part in the primary, or a turnout of around 30-35 percent, according to his office.

Data from the Alabama Secretary of State’s office for the 2016 presidential election, the 2017 special Senate election and the 2018 governor’s race shows which counties tend to be best at getting out the vote.

The presidential election, as is usually the case, saw the highest turnout, while the 2017 special election saw a much lower turnout. The 2018 governor’s race was right in the middle.

So which areas tend to have the highest turnout?

Alabama richest and poorest counties lead the way in voter turnout | Graphic by Ramsey Archibald

Several of the poorest counties in the state - and one of the richest - typically see high turnout. Greene County, the smallest county in the state in terms of population, and the poorest in terms of median household income, had the highest turnout for those three elections. On average, just over 62 percent of the county’s roughly 7,000 active voters participated in the statewide elections in 2016, 2017 and 2018.

Greene is one of a handful of smaller counties at or near the top of the list, but at least one of Alabama’s larger counties has above-average turnout, too.

Shelby County, just south of Birmingham and the richest county in the state in terms of median household income, is the county with the sixth-most eligible voters in Alabama. It’s second in voter turnout. Just over 60 percent of its 149,000 active voters participated in the last three statewide elections, according to the Secretary of State’s office.

The other counties in the top five are clustered around Greene, either in or near the Black Belt. Pickens County, on the Mississippi Border, had an average turnout of 60 percent, with just over 14,000 active voters in 2018. Just over 59 percent of Sumter County’s 10,000 active voters took part in those elections, and just under 59 percent took part in Marengo County. There were 16,100 active voters there in 2018.

Jefferson County, the largest county in the state by population, saw the 8th highest turnout at just under 58 percent. There were 480,000 active voters there in 2018.

Madison County, home of Huntsville, was just behind Jefferson at 9th, with a turnout of 57.5 percent. Montgomery sat at 54.5 percent, while Mobile’s turnout during the last three elections was 50.3 percent - 16th worst in the state.

The state average turnout for those elections was 53.7 percent.

Many of the counties with the lowest voting percentages can be found in the eastern half of the state, and especially along the border with Georgia. The 11 counties with the lowest turnout over the last three statewide elections are either on the border or one county removed.

Russell County, the eastern-most county in the state, is the county with the lowest turnout. Just 42.7 percent of eligible voters took part in those elections, on average. It’s one of just 13 counties to average less than 50 percent turnout over that stretch.

In 2018, following the primary, Secretary of State Merrill raised questions about the high voter turnout in some Black Belt counties.

Such questions predate Merrill. Greene County, especially, has had its share of issues - 11 people were convicted of absentee voter fraud there 20 years ago. And there are a handful of counties with more active, registered voters than there are adults, according to the U.S. Census Bureau. Merrill’s office this week explained that some difference in active voting rolls and Census population estimates is expected, and doesn’t mean rolls are inflated or that ineligible voters haven’t been removed from voting rolls.

Do you have an idea for a data story about Alabama? Email Ramsey Archibald at rarchibald@al.com, and follow him on Twitter @RamseyArchibald. Read more Alabama data stories here.