It may be hard to think about reapportionment and redistricting during the heat of a presidential election cycle, but they are right around the corner. So we thought it would be a good time to break down how the states will draw their new district lines after the 2020 Census is completed.

If Virginia voters approve a question on the November ballot to join nine other states with a bipartisan or nonpartisan congressional redistricting commission, a total of 125 congressional seats out of 435 will have their lines drawn in either a bipartisan or nonpartisan fashion.

Another 58 seats will be drawn in three states where courts have enforced partisan fairness standards: Florida, North Carolina, and Pennsylvania. In each case, those maps have been redrawn during the past decade—to Democrats’ benefit.

For another 51 seats, the lines will be drawn by the legislature but in states where the governor is of a different party from the legislature or the legislature has split partisan control. (Some of these states currently have legislative supermajorities for the majority party, however, meaning they could override a gubernatorial veto.)

And there are six at-large seats where redistricting is moot. (Montana is a seventh at-large seat, but we’ve categorized it as a commission state for this analysis because it may gain a second seat through reapportionment in 2020.)

If you add these categories up, the House has 240 seats that can’t be easily gerrymandered. That’s a majority — 55 percent — of all House seats.

For the remainder of House seats, 129 are in states with total Republican control, known as a trifecta, and 66 are in states with total Democratic control. Some of these states have hybrid systems for redistricting that include bodies such as backup commissions if the legislature fails to come to an agreement. Still, we’re categorizing them as partisan for this analysis because the legislature maintains a strong, even dominant, role in the process.

This imbalance puts Republicans in a better position than Democrats to be able to gerrymander a new decade’s worth of lines, although the lines they draw will account for only a fraction of the seats in the House.

The number of seats that will be drawn without a chance to gerrymander will actually increase slightly if you account for projected seat gains and losses after the 2020 Census. A net gain of three additional seats will be drawn by commissions or divided government if the current reapportionment projections hold. (Further below, we’ll list elections in November that could change the calculus for redistricting.)

And the number of seats that can’t easily be gerrymandered has increased significantly since the last round of redistricting in 2010. New commissions will be in force for 21 seats next year, a number that rises to 32 if Virginia voters approve theirs in November. Meanwhile, an additional 58 seats are in states that have experienced court rulings that limit partisanship in redistricting. Combined, that’s 90 seats that could be gerrymandered after the 2010 Census but shouldn’t be next year. And another 43 seats are in states that have approved less sweeping efforts to diminish gerrymandering.

Here’s the full breakdown by redistricting method, followed by state-by-state thumbnails. Numbers in parentheses after a state’s name refer to the current number of House seats. A plus or minus number denotes the number of seats the state is projected to gain or lose after the 2020 Census.

Breakdown using current apportionment:


Iowa (4): Unique among states, Iowa hands map-drawing duties to nonpartisan legislative staff that may not consider partisan factors nor incumbency. The legislature must vote on the map provided, with a simple majority needed to pass. Since 1980, when the system was implemented, the legislature has always adopted a map drawn by the staff.


Arizona (9) +1: Adopted by a citizen initiative in 2000, Arizona’s commission has equal representation from both parties and an unaffiliated tiebreaker as chair.

California (53) -1: California adopted its commission for congressional redistricting in 2010 by citizen initiative. Maps must be approved by a supermajority, including at least three votes from the panel’s Democratic, Republican and unaffiliated representatives.

Colorado (7) +1: In 2018, Colorado voters approved a commission for redrawing congressional districts. Approval requires at least two votes from unaffiliated commissioners.

Hawaii (2): Hawaii’s reapportionment commission, created by the legislature in 1992, approves new maps by a simple majority without a bipartisan vote requirement.

Idaho (2): Created by the legislature in 1994, Idaho’s commission requires a simple majority, with no bipartisan vote requirement.

Michigan (14) -1: Michigan voters approved a commission system in 2018 and it will be used for the first time after the 2020 Census.

Montana (1) +1: Montana currently has only one House seat, but the coming round of reapportionment could bring a second seat. If that happens, the map would be drawn by a commission.

New Jersey (12): In 1995, voters approved a congressional redistricting system. The tiebreaking commissioner has often been an academic.

Washington (10): Created by the legislature in 1983, Washington state’s commission includes equal numbers of Democrats and Republicans and has a non-voting, unaffiliated chair. Passage requires a supermajority. Once passed, the legislature can amend the commission’s maps with a two-thirds vote.


Virginia (11): Voters in November 2020 will be asked to approve a legislature-passed constitutional amendment to create a redistricting commission that includes legislators and citizens.


Florida (27) +2: The legislature draws districts, which can be vetoed by the governor. However, the maps must now take into account fairness requirements approved by the voters.

North Carolina (13) +1: The legislature draws districts without a gubernatorial veto. However, the state supreme court in 2019 struck down the congressional district map for being too partisan, and the ruling is expected to carry weight going forward.

Pennsylvania (18) -1: The legislature draws districts, which can be vetoed by the governor. In 2018, the state supreme court struck down the congressional district map for being too partisan. This ruling is expected to carry weight going forward. The legislature has also considered legislation to change how redistricting is done.


Connecticut (5): If the legislature cannot muster a two-thirds majority vote, redistricting goes to a backup commission, which is composed of nine members (two each are chosen by the Senate president pro tem, the Senate minority leader, the House speaker and the House minority leader, and they choose a ninth member). The backup commission has drawn every map since 1981.

Illinois (18) -1: If the legislature fails to approve a map, the task falls to a backup commission.

Maine (2): A legislative apportionment commission made up of legislative appointees and members of the public offers maps that the state legislature must approve, unmodified, by a two-thirds majority. If they fail to do that, the legislature can draw up maps on its own, and if the legislature fails to do so, the state supreme court steps in.

New York (27) -1: In 2014, voters approved a constitutional amendment from the legislature for an advisory commission. If the legislature rejects the commission’s first map, the commission will redraw the map and submit a second version to the legislature. Only after a second rejection does the legislature get to draw districts on its own. The number of legislative votes required to approve a commission-drawn map varies, depending on the partisan makeup of the legislature. (This system could change if a proposed constitutional amendment passes in 2021.)

Oregon (5) +1: If the legislature fails to enact maps, the chief justice of the state supreme court appoints retired judges to a panel that adopts congressional districts for the court to review and approve.


Ohio (16) -1: In 2018, voters approved a constitutional amendment from the legislature to create a multi-step process for redistricting. The legislature gets first crack, and if it passes by a three-fifths margin in each chamber, including half the members of the two largest political parties, it becomes law. If it doesn’t, a commission is empaneled, and if the commission fails, the task goes back to the legislature, which can act by majority vote. However, if maps are adopted without bipartisan support, they are good for only four years.

Utah (4): In 2018, Utah voters approved a citizen initiative, later modified by the legislature, to establish an advisory commission. The votes of at least five commissioners are enough to recommend a map to the legislature, which must consider it as is. If the legislature rejects the map and draws its own, it must explain why its map is better.


Alabama (7) -1
Arkansas (4)
Georgia (14)
Indiana (9)
Mississippi (4)
Missouri (8)
Nebraska (3)
Oklahoma (5)
South Carolina (7)
Tennessee (9)
Texas (36) +3
West Virginia (3) -1


Nevada (4)
New Mexico (3)
Rhode Island (2) -1


Note: Of the following states, four – Kansas, Kentucky, Maryland, and Massachusetts – currently have legislative supermajorities that can override a gubernatorial veto. That could change with the 2020 elections, perhaps in Kansas.

Kansas (4)
Kentucky (6)
Louisiana (6)
Maryland (8)
Massachusetts (9)
Minnesota (8) -1
New Hampshire (2)
Wisconsin (8)


North Dakota
South Dakota


One state with a GOP trifecta has a competitive gubernatorial race this fall: Missouri, where the governor is incumbent Republican Mike Parson.

Several states have competitive contests to control the legislature that could affect redistricting prospects.

Perhaps the biggest is Texas, where the Cook Political Report rates the state House Lean Republican. If the Democrats manage to take over the state House, they would have a voice in redistricting even though the state has a GOP-controlled state Senate and a Republican governor. Texas has spent years in court during recent cycles defending maps that Democrats have challenged.

Another is North Carolina, where the legislature draws the lines without gubernatorial veto power. We rate both the North Carolina House and Senate as Lean Republican.

In Minnesota, the Republican-held Senate is rated a Tossup. If the Democrats managed to take control, they would have a trifecta.

In Pennsylvania, both legislative chambers are held by Republicans but rated lean Republican. If the Democrats flip the chambers, they would have a trifecta.

In both Florida and Georgia, the GOP has a trifecta, but a strong Democratic wave could theoretically flip a chamber or two in each state, giving Democrats a voice.

Meanwhile, Texas and North Carolina also have supreme court elections in November that could shape the redistricting process if the maps are eventually taken to court.

In Texas, four Republican incumbents on the court are facing Democratic opponents in an election year in which Democratic presidential nominee Joe Biden is running almost neck and neck with President Donald Trump.

In North Carolina, the Democrats have a 6-1 edge on the state supreme court, but two of their incumbents are facing Republican challengers this fall, and the one Republican-held seat is open.

Meanwhile, in New Mexico, the Democrats have a 4-1 edge on the state supreme court, but two Democratic incumbents must stand for partisan election. While the state has been trending Democratic, a loss of both seats would give Republicans the edge on the court.

Two other presidential battleground states – Michigan and Ohio -- have closely watched supreme court races in November that could flip the court’s partisan control from Republican to Democratic.

The role of these courts in redistricting could be limited in Michigan, due to its new commission system, though the justices could still have an impact if they are asked to make rulings that affect what the commission can do. The new court in Ohio could also have an impact if aspects of the state’s new and somewhat complicated hybrid redistricting system end up in court.

Photo Credit: AP Photo/Carolyn Kaster

More from the Cook Political Report