How do political parties decide who will be on the ballot under their sponsorship?

Political parties typically decide who will be on the ballot through a combination of primary elections, caucuses, and party conventions. Candidates often compete in primaries to secure delegates who support them at the party convention, where the official nominee is chosen. Additionally, party leadership may influence the selection process by endorsing candidates or setting criteria for candidacy. Ultimately, the chosen candidate must align with the party's platform and appeal to its voter base.