Glenn Hegar
Texas Comptroller of Public Accounts
Glenn Hegar
Texas Comptroller of Public Accounts
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Glenn Hegar
Texas Comptroller of Public Accounts
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A Review of the Texas Economy


Redistricting 101 How Census Data Affect Elections

by Patrick Graves Published January 2020

The decennial census serves many purposes, but perhaps none is more significant or far-reaching than the basis it provides for redistricting.

Many state and federal officials represent districts that are intended to reflect equalized populations. Therefore, their sizes and shapes must be redefined every 10 years to reflect population growth or decline and other demographic changes. Redistricting, then, is the process of redrawing district boundaries to guarantee equal voter representation through equal, or equivalent, population counts.

Another process directly linked to the census is reapportionment, which occurs primarily at the federal level. Reapportionment allocates the number of seats in a legislative body to account for population changes. The U.S. House of Representatives currently has a total of 435 seats, distributed among the states according to census population figures. By contrast, the U.S. Senate has 100 seats — two per state, regardless of population.

The Texas Legislature also has a fixed number of seats in both houses — 31 in the Senate and 150 in the House. Texas’ legislative districts change every 10 years, but the total number of lawmakers doesn’t.

In addition to the Legislature and the U.S. House, the State Board of Education (SBOE) and state judicial districts undergo redistricting after each census, as do some local governmental bodies (including city councils, county commissioners courts and school district boards).

Each state’s representation in the Electoral College, which selects the president, also is subject to change based on census population counts.

Fast Growth Equals More Lawmakers

Texas has been growing rapidly for decades, with a population now estimated at more than 29 million. From 2010 through 2018, the number of Texans rose by 14.1 percent, more than double the national growth rate of 6 percent; only Utah grew faster (14.4 percent). Between 2017 and 2018, Texas added more than 1,000 residents a day. About half of them migrated to the state, according to U.S. Census Bureau officials; the rest represent “natural increase,” or births exceeding deaths.

Unsurprisingly, Texas’ largest metropolitan areas are seeing the greatest population gains, as seen in data from the Comptroller’s economic regions (Exhibit 1). Only the rural Northwest Region’s population declined slightly between 2010 and 2018.

The 2020 census, then, is likely to increase Texas’ representation in Congress. The Lone Star State currently has 36 U.S. representatives and is expected to pick up three or four additional seats during the next round of reapportionment.

By law, the Census Bureau must send the 2020 population figures to the president by Dec. 31, 2020, for the reapportionment of U.S. House seats. For redistricting purposes, the data must arrive at statehouses by April 1, 2021, but Texas legislative officials expect the numbers sometime in late February.

Exhibit 1: Texas Population Growth by Comptroller Region, 2010-2018

Region Percent Change
Capital Region (includes Austin) 25.2%
Gulf Coast Region (includes Houston) 17.8
Metroplex Region (includes Dallas & Fort Worth) 16.9
Alamo Region (includes San Antonio) 16.1
Texas 14.1
West Region 14.0
Central Region 9.5
South Region 7.4
United States 6.0
Upper Rio Grande Region 4.9
High Plains Region 4.0
Upper East Region 3.7
Southeast Region 1.8
Northwest Region -0.1

Source: U.S. Census Bureau, Texas Comptroller of Public Accounts and Texas Demographic Center

Drawing Lines

Although actual mapmaking for state and federal redistricting is more than a year away, the process is already in motion in Texas. In 2019, the redistricting committees of the Texas House and Senate began conducting public hearings on their respective plans that will continue into 2020; they’ll also hold hearings during the 2021 legislative session.

Members are hearing testimony from subject-matter experts as well as policy advocates, interest groups and the general public. Their purpose is to gather stakeholder input on their concerns and preferences about the geographic areas and other elements districts should, and should not, include.

The Texas Legislative Council (TLC) assists lawmakers throughout this lengthy process. During the next legislative session, its staff will enter relevant census data into a computer program designed specifically for creating district maps. Mapmaking begins after the data are verified and the application is tested. Members of the public will have access to the same program (RedAppl) to draw alternative maps for legislators’ consideration, or can submit maps created using other, compatible software.

Redistricting legislation follows the same path as all other bills, except that the House and Senate plans traditionally originate in their respective chambers. Because regular sessions conclude at the end of May, legislators typically have about 12 weeks to complete this task.

As in most states, Texas lawmakers will draw the initial lines both for legislative and congressional districts. These redistricting maps often are challenged, however; it would be almost unprecedented if at least some redistricting plans didn’t wind up in state or federal court. Texas is so diverse, with so many competing political interests, that, as Austin attorney and election law expert Robert Heath notes, “Somebody’s going to get left out. Someone’s not going to be satisfied. It’s a high-stakes game. There are probably going to be challenges. Whenever you draw [a new map], it changes everything.”

This means that judges could end up deciding some districts’ final boundary lines.


Under the U.S. Constitution, the Electoral College, not voters, actually chooses the president (and vice president). And the census determines the number of each state’s electors.

The allocation is one elector per House member, plus one for each of the two senators; thus, each state is guaranteed at least three (several sparsely populated states have only one representative). Texas currently has 38 electors, second only to California’s 55; New York and Florida are tied for third place at 29 apiece.

The top 10 electoral states (in rank order) are California, Texas, Florida, New York, Pennsylvania, Illinois, Ohio, Georgia, Michigan and North Carolina. They include nearly half (47.6 percent) of all electoral votes.

Texas has never lost an elector and has added them after almost every census cycle. This time it should add three to four more, while California could lose one.

Note: The District of Columbia gets three electoral votes.
Source: National Archives and Records Administration

Other Types of Redistricting

The Legislature also redraws boundaries for the State Board of Education (SBOE), which sets policies and adopts standards for Texas public schools and oversees the Texas Education Agency and the Permanent School Fund. The board’s 15 members are elected from single-member districts across the state, each representing roughly 1.8 million Texans.

In addition, the Legislature creates districts for the state’s 469 district courts. As of 2018, according to the Office of Court Administration (PDF), 371 of these court districts covered a single county and 98 contained more than one county. These district boundaries, however, are subject to criteria based on efficiency and “judicial burden,” determined largely by caseloads and other factors unrelated to population. If the Legislature doesn’t redraw them by June of the third year after the census, the state’s Judicial Districts Board must do so by August of the same year. Failing that, the task falls to the Legislative Redistricting Board.

The state’s appeals courts also are organized by district, 14 in all. Their boundaries are set at the Legislature’s discretion and not subject to any timetable for redrawing.

Role of the Legislative Redistricting Board

If state House and Senate districts aren’t adopted during or soon after the first regular session following the census, the Legislative Redistricting Board (LRB) steps in. (It has no jurisdiction over congressional districts.) The board, comprising the lieutenant governor, speaker of the House, attorney general, comptroller and land commissioner, last convened in 2001, the third time it’s done so since its inception in 1951.

If the Legislature doesn’t approve new legislative maps, if the governor vetoes those maps (and the vetoes aren’t overridden) and/or if courts overturn them within three months of adjournment, the Texas Constitution requires the LRB to meet within 90 days of the session’s end. The LRB must create and adopt its own plans, by simple majority vote, within 60 days of convening. The governor cannot circumvent the LRB or veto any plans it approves. If it fails to do so, however, the governor may call a special session of the Legislature, or the courts may intervene.

Exhibit 2 depicts the redistricting timeline for the 2020 census, including options for LRB involvement and special sessions.

Again, the LRB’s authority extends only to redistricting for the Legislature. The governor may reconvene the Legislature if it fails to redraw congressional and/or SBOE district boundaries during the regular session. (SBOE redistricting is referenced in but not required by state law.) If not, state or federal district courts typically draw those maps.

Exhibit 2: Redistricting Timeline, 2020-2022

Legislative Redistricting Board (LRB)

  • LRB assumes responsibility for house and senate plans if bills have not passed or have been vetoed.
  • LRB must convene within 90 days of sine die
  • LRB must complete its work within 60 days of convening.

Special Sessions

  • Legislature may consider Congressional and SBOE redistricting plans in special session.
  • Governor may call special session to consider house and senate redistricting plans (only after time in which LRB can meet).

Judicial Review

  • May occur if court challenges are filed against enacted districts.
  • Apri 1, 2020: Census Day
  • November 3, 2020: General election. Last held under 2010-cycle districts
  • January 12, 2021: 87th Legislature convenes
  • February 2021: Expected delivery of census data to Texas
  • March 12, 2021: 60-day bill filing deadline; includes redistricting bills
  • May 31, 2021: 87th Legislature adjourns sine die
  • June 20, 2021: Last day for governor to sign or veto regular session bills
  • August 29, 2021: Last day that LRB could convene
  • October 28, 2021: Last day that LRB could meet
  • December 13, 2021: Filing deadline for 2022 primary elections
  • March 1, 2022: First elections held under new districts

* “Census Day,” April 1, 2020, is the date by which every American home should have received its invitation to participate in the census.
Source: Texas Legislative Council


Texas Election Code Section 172.023 sets the filing deadline to declare candidacies for spring primary elections on the second Monday of December in odd-numbered years; in 2021, it’s Dec. 13. This allows about six-and-a-half months from the end of the regular session for:

  • the governor to act on any redistricting legislation passed;
  • the LRB to meet, if necessary;
  • the Legislature to reconvene in a special redistricting session, if called;
  • counties to make any necessary conforming changes to their election precincts resulting from new district boundary lines; and
  • opponents to mount any legal action and courts to issue any rulings.

Legal Criteria

All legislative, congressional and SBOE districts must meet two basic criteria set forth in the federal Constitution and laws: equal or near-equal populations and preservation of the right to vote regardless of race, color or language. The controlling standard is “one person, one vote.”

For U.S. House districts, this means their populations must be close to equal. Texas House and Senate districts generally may deviate by up to 10 percent (from most to least populous) from the ideal district population (i.e., the number of residents if all districts were populated equally). Texas Senate districts must be contiguous and represented by only one senator per district.

In addition, state House districts must adhere as closely as possible to four rules designed to preserve the integrity of counties:

  1. A county must form a single district if its population is sufficient for one.
  2. If a county’s population is less than the required number for one district, it must remain intact and be combined with one or more contiguous counties.
  3. Counties capable of populating two or more whole districts must be so divided, with no district extending into another county.
  4. Counties that can populate one or more whole districts plus a portion of another must form that many whole districts; the excess population then must be combined with another district in a contiguous county or counties.

Courts have allowed these rules to be bent to preserve equal representation (the one person, one vote principle).

Along with equal population, other key criteria include compactness, contiguity, partisan and racial fairness and the preservation of existing political communities. Local preferences, voting patterns and communities of interest also must be taken into consideration. FN

For more information on the redistricting process in Texas, visit the Texas Legislative Council.