BATON ROUGE, LA. — Wednesday's the deadline to register to vote or to change parties for the presidential preference primary next month. Registered Democrats and Republicans will vote on March 24 for who they want to get their party's nomination. Only people registered in a party may vote in that party's primary. Early voting runs from Saturday, March 10 through Saturday, March 17. Voters also will elect candidates for the Republican and Democratic state and  local governing bodies.