Which statement best describes the invisible primary?

The invisible primary refers to the period in the presidential nomination process that occurs before the formal voting begins, during which candidates engage in activities that can influence their chances of securing their party's nomination. This phase is characterized by informal activities, such as fundraising, building a support network, and participating in debates or discussions, rather than engaging in official delegate selection processes.

During the invisible primary, candidates work to gain media attention and establish their credibility with party elites and voters, often without any formal rules governing delegate selection. This period is crucial as it sets the stage for how candidates are viewed ahead of the actual primaries and caucuses, but it does not involve any official voting or delegate allocation.

The other options suggest varying degrees of structure and timing that do not accurately reflect the nature of the invisible primary, such as formal rules and exact start dates, which are more relevant to the later stages of the nomination process when official elections are held.