Pity the candidate who tries to make people remember to go vote Tuesday in Mississippi’s congressional primary runoffs.

Political scientist Marty Wiseman said runoffs usually have significantly lower turnout than primaries.

“But when it’s over, a win’s a win,” said Wiseman, director of Mississippi State University’s John C. Stennis Institute of Government. “There have been some folks who’ve had long careers in politics after winning with low turnout.”

Polls will be open 7 a.m.-7 p.m. Tuesday in two of Mississippi’s four congressional districts.

North Mississippi’s 1st District has a runoff for each of the two major political parties. The Republican contest is between Southaven Mayor Greg Davis and former Tupelo Mayor Glenn McCullough Jr. The Democratic contest is between Prentiss County Chancery Clerk Travis Childers of Booneville and state Rep. Steve Holland of Plantersville.

In central Mississippi, there is a 3rd District Republican runoff between two attorneys from Rankin County — Gregg Harper of Pearl and former state Sen. Charlie Ross of Brandon.

The primaries were three weeks ago.

The March 11 ballots included Democratic and Republican presidential races, which traditionally generate a great deal of voter interest. There are no runoffs for the presidential primaries.

Winners advance to the Nov. 4 general election.

People who voted in Democratic primaries March 11 are not allowed to vote in the Republican runoffs, and people who voted in the Republican primaries are not allowed to cross over to the Democratic runoff.

The 3rd District stretches from Natchez in the southwestern corner of the state to the Jackson suburbs in central Mississippi and to Starkville in the Golden Triangle. Because the 3rd District is drawn to favor Republicans, it’s likely that the winner of the Harper-Ross race will go on to defeat the Democratic nominee, Joel L. Gill of Pickens, in the general election.

Rankin County is one of the most heavily Republican parts of the state, and because Ross and Harper both live there, it will be vital deciding the winner. Wiseman said Monday the candidate who runs stronger in another population base, Meridian, “gets the edge.”

The 1st District includes DeSoto County and the northern cities of Oxford, Tupelo, Columbus and Booneville.

It’s unusual for Mississippi to have two of its four U.S. House seats come open in the same year.