Final answer:
The direct primary reform allowed voters to choose candidates to run for public office.
Step-by-step explanation:
The reform that allowed voters to choose candidates to run for public office is the direct primary. A direct primary is an election where voters cast their ballots to select nominees for upcoming elections. This reform ensured that voters could directly pick candidates for public office rather than relying on party bosses or state legislatures to make the decisions. This change was part of the broader movement for citizen participation in the electoral process and aimed to give citizens more power and a direct connection with their government.