Final answer:
Polarization in Congress has increased over the past 50 years due to growing party cohesion and a decrease in moderates. This trend has both positive and negative consequences for democracy and policymaking.
Step-by-step explanation:
Polarization in Congress has been increasingly common over the past 50 years as the parties have grown more internally cohesive. This has caused a greater divide between the parties and a decrease in moderates. In recent decades, there has been less cross-party socialization and bipartisan cooperation, resulting in more partisan and ideologically motivated voting.
This trend of polarization in Congress has both positive and negative implications. It provides voters with distinct choices and competitive parties, which is a sign of a thriving democracy. However, it also makes it difficult for elected officials to achieve their policy goals and hinders bipartisan cooperation on important issues.