Final answer:
Primary elections and caucuses allow voters to choose candidates for the final election based on candidates' popular appeal and grassroots support. These processes shape the overall race by determining the field of candidates.
Step-by-step explanation:
Primary elections and caucuses are held before the general election to allow voters to choose candidates for the final election. These processes test candidates' popular appeal and their ability to mobilize and organize grassroots support. Primaries can either give all delegates to the winner or distribute them proportionately to voter support. The order in which these events are held shape the overall race by shaping the field of candidates. Overall, primary elections and caucuses provide an opportunity for voters to have a direct say in the selection of candidates for the general election.