Final answer:
Progressives aimed to empower voters in the presidential selection process by implementing primaries to ensure direct citizen participation in nominating candidates.
Step-by-step explanation:
Progressives sought to give voters more power in choosing the President by implementing primaries. This initiative was part of a broader effort by Progressive reformers to promote wider citizen participation in the electoral process and to challenge the control political machines had over the process. The introduction of the direct primary allowed voters to cast ballots to select nominees for upcoming elections, thereby ensuring that the selection of candidates for office would be more firmly in the hands of the people rather than party elites and bosses.