Final answer:
The percentage threshold requiring primary elections for political parties is 50 percent, known as majority rule. If no candidate surpasses this in the primary, a runoff election is held to ensure a candidate wins a majority.
Step-by-step explanation:
The percentage threshold that requires political parties to hold primary elections is typically 50 percent of the vote, known as majority rule. In states like Georgia, if a candidate in a primary election does not secure this majority, it triggers a runoff election where the top candidates compete again to ensure a clear winner is chosen with a majority of votes. The primary serves as a crucial step in the nomination process where the party's candidate must win enough delegates or collect sufficient signatures to be placed on the ballot for the general election.
Political parties in some states use different types of primaries including open, closed, and runoff primaries as part of their nominating process. In open primaries, all voters can choose which party's primary to vote in, whereas in closed primaries, only registered party members can vote. The run-off primary is held if no candidate wins more than the designated 50 percent in the initial primary.