Which group of individuals primarily votes for U.S. Senators?

The primary group of individuals who votes for U.S. Senators is the general population of the state. This is grounded in the principles of democratic representation established by the 17th Amendment to the U.S. Constitution, which was ratified in 1913. This amendment transitioned the election of Senators from being appointed by state legislatures to direct election by the voters of each state.

As a result, every citizen eligible to vote in a given state, after meeting specific criteria such as age and residency requirements, has the right to participate in elections for U.S. Senators. This system ensures that Senators are accountable to the public they represent, reflecting their constituents' needs and perspectives.

The involvement of state legislators, governors, and members of Congress in the election process of U.S. Senators is limited or indirect in comparison to the direct electoral role the general population plays, thereby reinforcing the democratic framework within which Senators are chosen.