Primaries and the Conventions
In a system with political parties, you need candidates who are aligned with parties. Parties choose their candidates who, if not members, are at least generally in agreement with the party, will join their legislative group if elected to a legislative position, and will generally vote to advance the interests of the people who comprise the party. Parties do this in a wide variety of means around the world. Some can be literally appointed by their leader, which happens in Canada in some instances, particularly in the case of an early election caused by the collapse of legislative confidence in a parliamentary system, or in areas where the party is weak or their local branches are corrupt. Some are chosen by a panel which acts for the purpose of considering candidates. New Zealand Labour uses this method using a few different selection groups to hold basically a job interview, advisory votes by the members, and the panel makes the final selection for each constituency, and for the Ne