Page "Article One of the United States Constitution" Paragraph 14

Since clause 3 provides that Members of the House of Representatives are apportioned state-by-state and that each state is guaranteed at least one Representative, exact population equality between all districts is not guaranteed and, in fact, is currently impossible, because while the size of the House of Representatives is fixed at 435, several states had less than 1 / 435 of the national population at the time of the last reapportionment in 2000.

However, the Supreme Court has interpreted the provision of Clause One that Representatives shall be elected " by the People " to mean that, in those states with more than one member of the House of Representatives, each congressional election district within the state must have nearly identical populations.