"People get confused because they think when they go to vote on Aug. 15, they're voting for their person. They are only voting for the nominee of their party and we need to remember that and that's why a cross over rule could be in effect and should be the choice of the party. But now that it's been cotified, it will be illegal if you vote in the nomination process for one party and the run off for the other party," Merrill said.