If any Democrat can be elected governor of Mississippi, it’s Jim Hood. The state’s four-term attorney general is the only Democrat who has won a statewide race in Mississippi in the last 16 years. That’s one reason Republicans are taking him seriously. Nevertheless, he faces an uphill climb in this year’s election, and an obscure provision in the state constitution may make it impossibly steep.

In Mississippi, it’s not enough for a gubernatorial candidate to win a majority of votes. He or she must also prevail in a majority of the state House districts. Otherwise, the election is thrown to the House to decide. It’s like a single-state Electoral College system.

Republicans are spread out around Mississippi, dominating rural districts, with Democratic voters concentrated in Jackson and some of the Delta counties along the state’s western edge. That makes Hood’s task of winning most of the state House districts fairly daunting. It won’t be sufficient for him to run up the score in Jackson or other blue enclaves. “The Trump realignment strengthened Republican numbers in Mississippi, largely because it brought over blue-collar Democrats,” says Brad Todd, a strategist for Lt. Gov. Tate Reeves, the GOP favorite for governor. “You can tell the Gulf Coast has gotten redder.”

In last year’s U.S. Senate contest, Democrat Mike Espy carried just 31 of the state’s 82 counties, although he came fairly close in the popular vote. But Democrats believe Hood maintains broader appeal. He’s won each of his four races for attorney general by double-digit margins. Not only is Hood the only Democrat who’s been successful lately in statewide politics in Mississippi, but he was also the only Democrat occupying a statewide constitutional office anywhere in the South prior to the election of Louisiana Gov. John Bel Edwards in 2015. “It’s not just Democrats who have supported him through the years,” says Michael Rejebian, Hood’s senior campaign adviser. “He appeals to a broad range of voters -- urban, rural, suburban, farmers, everybody.”

Because the question of who won the most House districts won’t matter until November, Rejebian says the campaign is grappling right now with about a thousand more pressing issues. But it’s something candidates have to think about every time there’s an election for governor. When Ronnie Musgrove became the last Democratic governor of the state in 1999, he and his Republican opponent won an equal number of state House districts. Musgrove had carried the state by a plurality and the House installed him in office.

But back then, the House was still controlled by Democrats. Republicans now control 74 of the 122 Mississippi House seats. GOP House members aren’t going to install a Democratic governor who fails to carry the state outright.