Final answer:
A party platform influences voters by simplifying a party's agenda, serving as a brand that encapsulates the party's principles and policy goals.
Step-by-step explanation:
A party platform influences voters primarily by simplifying a party's agenda. A platform is a written document that outlines the policies, positions, and principles of a party. It helps to signal to voters what the party stands for and promotes coherence among the party's candidates.
The origins of a party platform date back to the early days of the United States, serving as a tool to unite various interests under a common vision. Major party candidates are elected based on their alignment with these platforms, which act as a heuristic for voters to make decisions, especially when information about specific candidates is scarce. Essentially, the platform provides cues that help voters quickly identify with the candidate's political beliefs and can encapsulate the essence of what the candidate aims to achieve if elected.