Vote in presidentials primaries – Oct 2020

Depending on voter eligibility conditions, primary elections may be open or closed (see Figure 1). In an open primary, a registered voter can vote in the Republican or Democrat primary, regardless of party membership. However, voters cannot vote in more than one primary. In a closed primary, a Democrat-registered voter may only vote in a Democratic primary, and so on. Intermediate systems have also been used, such as the semi-closed primary, in which participation is open to both registered party members and unaffiliated voters. Nevertheless, unaffiliated voters may choose which to vote in, while registered voters may only vote in the respective party primary. The party affiliation requirement for voting in primary elections has been subject to a number of Supreme Court opinions