Someone currently holding office and running for reelection.

A group that raises and spends money to elect and defeat candidates.

Redrawing district lines to favor one political party.

A district where one party has a large electoral advantage.

An election held in the middle of a presidential term.

An election to select a party's nominee for the general election.

A meeting of party members to select candidates.

When the presidency and Congress are controlled by different parties.

The percentage of eligible voters who cast a ballot.

The main election between candidates from different parties.

All seats up for election every two years, representing local districts.

One-third of seats up for election every two years, representing entire states.

Raise and spend money to support candidates, often favoring incumbents.

Cause: Name recognition, fundraising | Effect: Higher reelection rates

Cause: Redrawing district lines | Effect: Safe seats, less competitive elections

Cause: Occur during a president's term | Effect: Referendum on president, shift in Congress

Cause: Different parties control presidency and Congress | Effect: Gridlock, difficulty passing laws

Cause: Gerrymandering or strong party loyalty | Effect: Less responsive politicians, extreme candidates

Cause: Apathy, lack of information | Effect: Skewed representation, policies not reflecting public will

Cause: Supporting aligned candidates | Effect: Incumbents favored, influence on policy

Cause: Previous office holding, media coverage | Effect: Easier to win elections

Cause: Unpopular policies, economic downturn | Effect: Losses in midterm elections

Cause: Successful policies, economic boom | Effect: Gains in midterm elections