Final answer:
The Progressive Era reforms in the United States impacted politics by increasing citizen participation and promoting democratic reform through direct election of senators and the implementation of direct democracy measures.
Step-by-step explanation:
The Progressive Era reforms outlined in the diagram significantly affected politics in the United States by increasing citizen participation and promoting democratic reform.
One key reform was the direct election of United States senators, achieved through the 17th amendment. This allowed citizens to directly choose their senators instead of having them selected by state legislatures.
Another reform was the implementation of direct democracy measures, such as the direct primary, initiative, referendum, and recall. These reforms gave citizens the ability to have a more direct influence on lawmaking and to remove corrupt or ineffective officials from office.