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Political Dictionary

Apportionment

Apportionment is the allocation of House seats among the states based on population.

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Definition

Apportionment is the process of dividing the 435 voting seats in the U.S. House of Representatives among the fifty states after each decennial census. Every state receives at least one seat, and the remaining seats are distributed using a mathematical method established by law.

Why It Matters

Apportionment changes each state’s representation in the House and usually its number of presidential electors. Population shifts can therefore alter national political influence.

How It Works

After the census, state population totals are entered into the statutory formula. States gain, lose, or retain seats. Each state then redraws congressional districts as needed.

History

The Constitution tied House representation to population. Congress later fixed the House at 435 seats and adopted the method of equal proportions for allocating seats.

Example

A fast-growing state may gain one House seat and one electoral vote, while another state loses one.

Common Misconceptions

  • Apportionment draws the district boundaries.
  • Every state receives seats strictly in exact proportion to population.
  • Senate seats are reapportioned after the census.