Three Republicans running for Mississippi governor are having their only debate before the party primary. The one-hour program begins at 7 p.m. Tuesday at the WJTV television studio in Jackson, and will air on statewide TV and radio and online. Two of the candidates — former Mississippi Supreme Court Chief Justice Bill Waller Jr. and state Rep. Robert Foster — have already debated. This will be the first time for Lt. Gov. Tate Reeves to take part.