Party Loyalty: Refers to the tendency of members of Congress to vote along party lines. They often align with their party's views and policies.
Constituent Opinion: Represents the viewpoints and preferences of constituents, who are the people living in a congressman's district. Their opinions can influence how a congressman votes.
Interest Groups: These are organizations formed around specific policy issues or industries that aim to influence lawmakers' decisions through lobbying efforts. Interest groups can impact a congressman's voting behavior by providing information, resources, and support related to their causes.