500
These are two potential causes of party polarization.
What are...
• Increasing reliance on ideologically driven
activists
• Ideologically-driven membership
• Gerrymandering
• Media effects on politics (e.g.,
fragmentation of traditional media;
consolidation of media ownership;
media focus on ideological extremism)
• Changing norms in Congress (e.g., lower
levels of trust or dislike among members;
shorter work week)
• Direct primaries – ideological voters in
congressional elections
• Changing campaign finance rules
• Rise of single issue interest groups
• Clear issue differences between the
parties