What is reapportionment connected to every 10 years in the United States?

Reapportionment in the United States is directly linked to the decennial Census, which occurs every ten years. This process involves the redistribution of congressional seats among the states based on population changes. Following the Census, each state’s population is calculated, and seats in the House of Representatives are allocated accordingly to ensure that representation reflects the current population distribution.

As populations grow or decline, some states may gain additional congressional seats while others may lose seats, leading to a shift in political power at the federal level. This process is crucial for ensuring that representation in the House remains fair and aligned with the demographics of the nation. The connection to the Census is foundational in maintaining the principle of "one person, one vote" as it seeks to provide equitable representation based on population rather than fixed geographic areas or historical standings.