About redistricting

Redistricting is the act of redrawing a voting district's boundaries. 2020 was the last major redistricting cycle.

Ballotpedia tracks which voting district boundary is in effect at a given time using start dates and end dates. The start date corresponds to the date when an officeholder swears into office, and the end date is the officeholder's last day in office.

A voting district boundary's start and end dates do not necessarily, and usually do not, equal the election date for that office. Ballotpedia determines which voting district will be used for which race based on several factors, including the voting boundary's start and end dates; the race year; the election date; the race's swearing in date; and whether the race is a regular or special election.

As an example, California's 22nd Congressional district has voting district boundaries with the following end dates.

• Pre-2020 redistricting boundary end date: 2023-01-02

• Post-2020 redistricting boundary end date: null (implying it will be used for the foreseeable future)

In 2022, California's 22nd Congressional district had a special election and regular election on the same date. How did we know which boundary would be used for each race?

For the 2022 special election, we knew that the pre-redistricting voting boundary was used, because

• It was a special election

• The election date was before the boundary's end date

For the 2022 regular election, we knew that the post-redistricting voting boundary was used, because the race's swearing in date was after the pre-redistricting boundary's end date.