At this time ,voters have the option of crossing party lines and voting for the candidates of their votes of their choice. In presidential election , their votes are not direct. Each stage has a number of "electors" corresponding to its number of senators and representatives in congress. These electors make up the Electoral College, as defined by The U.S. Constitution. Electors, using the popular votes of their states' voters, really elect the President and Vict President.
Primaries and general elections have different rules and processes. The opportunity to make choices about public offcials is an essential part of the democratic process.