The WA state presidential primary is the voters' chance to help the major political parties choose presidential nominees. The primary will be open, meaning any registered voter can participate in either the Democratic or the Republican primary. Voters must mark and sign party declarations on their ballot return envelopes. However, voters who attended the Democrat Caucus can not declare themselves to be Republican for the primary. The results of the primary will be used to allocate delegates to the Republican National Convention, but not the Democratic National Convention, which will use the caucus system instead. More information