Congressional Behavior

What motivates members of Congress? How do they decide what to do?

Theories of Representation

How should a representative represent?

The Delegate Model

Representatives should vote the way their constituents want, even if they personally disagree.

Advantages: Democratic responsiveness. The people’s will is directly expressed.

Problems: Constituents may be uninformed, misinformed, or divided. What does “the district’s view” even mean on complex issues?

The Trustee Model

Representatives should use their own judgment, voting for what they believe is best for their constituents and the nation.

Edmund Burke’s classic statement: “Your representative owes you, not his industry only, but his judgment; and he betrays, instead of serving you, if he sacrifices it to your opinion.”

Advantages: Representatives can consider long-term consequences, expert knowledge, and national interests that constituents might not appreciate.

Problems: Elitist. Who decides what’s “best”? Can become an excuse for ignoring constituents.

The Politico Model

Representatives switch between delegate and trustee depending on the issue.

• High-salience issues (those constituents care deeply about): Act as delegate
• Low-salience issues (technical matters most constituents don’t follow): Act as trustee

This is probably closest to how most members actually behave.

Partisan Voting and Polarization

Party-Line Voting

Members increasingly vote with their party. The percentage of “party unity votes” (where a majority of one party opposes a majority of the other) has risen dramatically since the 1970s.

Why?

• Ideological sorting: Liberal Republicans and conservative Democrats have mostly disappeared
• Safe districts: Gerrymandering creates districts where the real election is the primary, which rewards partisan extremism
• Media environment: Partisan media reinforces ideological positions
• Party pressure: Leadership controls committee assignments, campaign funding, and floor time

Polarization

The ideological gap between the parties has widened. There’s almost no overlap between the most liberal Republican and the most conservative Democrat.

Consequences:

• Gridlock: Harder to pass legislation when parties can’t compromise
• Partisan conflict: More filibusters, more brinkmanship, more government shutdowns
• Decline of regular order: Bills bypass committees; omnibus packages replace individual appropriations bills

The Electoral Connection

Members of Congress want to be reelected. (David Mayhew’s foundational insight.) Almost everything they do can be understood through this lens.

Incumbency Advantage

Incumbents almost always win. House incumbents win about 90% of their races.

Sources of advantage:

• Name recognition: Voters know who they are
• Franking privilege: Free mail to constituents
• Campaign finance: Donors give to likely winners; incumbents are likely winners
• Constituent service: Years of casework builds goodwill
• Credit claiming: “I brought this project to our district”
• Gerrymandering: Districts drawn to protect incumbents

The Permanent Campaign

The two-year House term means members are always running. They spend enormous time fundraising. Some estimates suggest members spend 30+ hours per week soliciting donations.

Divided Government

When one party controls the presidency and the other controls at least one chamber of Congress, we have divided government.

Effects:

• More difficult to pass legislation: Need cross-party coalitions
• More oversight of the executive: Congressional investigations increase when Congress and the president are from different parties
• More use of executive orders: Presidents bypass Congress through unilateral action
• Potential for gridlock: Especially on divisive issues

Divided government has been common since the 1970s.

Gerrymandering and Redistricting

Every ten years, after the census, congressional districts are redrawn. This process is controlled by state legislatures in most states.

The Gerrymander

Drawing district lines for political advantage.

Techniques:

• Packing: Concentrate opposition voters in few districts (they win big but in fewer places)
• Cracking: Spread opposition voters across many districts (they never reach a majority)

Key Cases

Baker v. Carr (1962): Redistricting is a justiciable issue (courts can review it). “One person, one vote” means districts must be roughly equal in population.

Shaw v. Reno (1993): Racial gerrymandering (drawing districts solely based on race) violates the Equal Protection Clause.

Rucho v. Common Cause (2019): Partisan gerrymandering is a political question that federal courts cannot adjudicate. States can gerrymander as much as they want for partisan advantage.

Effects

Gerrymandering creates safe seats. Safe seats reduce general election competition. Reduced competition means primaries determine outcomes. Primary voters tend to be more ideologically extreme. This contributes to polarization.

Midterm Elections

Elections held in the middle of a presidential term, when only Congress is on the ballot.

Key patterns:

• Lower turnout: Without a presidential race, fewer people vote
• President’s party usually loses seats: Average loss is about 25 House seats
• Referendum on the president: Voters express approval or disapproval of presidential performance

The 2018 and 2022 midterms followed this pattern somewhat, though 2022 was historically mild for the president’s party.

Lame Duck Presidents

A president in their final years (especially after midterm losses) has reduced legislative power. Members of Congress look to the future; an outgoing president can’t help or hurt their careers.

Lame duck presidents often:

• Issue executive orders
• Make judicial appointments
• Focus on foreign policy (where they have more unilateral power)

The Takeaway

Congressional behavior is driven by electoral incentives, party pressure, and institutional rules. Members want to be reelected. Parties want to win majorities. These incentives shape everything.

Polarization and gerrymandering have made Congress more partisan and less deliberative. Divided government has become more common and more contentious. The institution the founders expected to be the center of government often seems paralyzed.

Understanding these dynamics helps explain why Congress acts (or doesn’t act) the way it does.