Clark is the state's chief elections officer. He predicts about 725,000 Mississippians will vote in Tuesday's party primaries for everything from governor to constable.
That would be higher than the approximately 700,000 who voted in the same party primaries four years ago.
Clark said today that his prediction is based on how many races are hotly contested at the state and county levels.
Mississippi has a population of 2.8 million and about 1.8 million registered voters.
Officials say many counties' registration books are inflated with names of people who have died or moved away.