The completely legal ways US politicians bend redistricting rules – a visual guide

·5 min read

Political strategists have long known that they can manipulate the electoral redistricting process.

In 1991, Republican mapmaker Thomas Hofeller said: “I define redistricting as the only legalized form of vote-stealing left in the United States today.” In the following decades, he drew gerrymandered maps that gave Republicans electoral advantages across the country.

What Hofeller knew was that the rules around redistricting are flexible. The constitution requires states to draw new electoral districts every 10 years, but there are few other hard and fast rules.

The US constitution gives state lawmakers the authority to draw electoral districts. So when state legislatures are controlled by one party and in charge of drawing new maps, they often draw districts that overwhelmingly favor their party, locking in victories for the next 10 years.

Party control map

It’s an advantage that can be quite severe – shutting the opposing party out from ever winning certain districts. It’s such a significant problem that a handful of states have chosen to strip lawmakers of their redistricting power, giving the power instead to commissions.

What are the map-making rules? And how can partisan lawmakers exploit the process to benefit their party?

How many shapes do you draw?

There are 435 representatives in Congress. Every 10 years, the US counts the number of people in each state and assigns a proportional number of representatives. Within their states, lawmakers also have to redraw state legislative districts – the same districts that they’re elected from.

So in 2021 states that have grown at a pace – Texas, Florida, North Carolina and Arizona, among others – will gain congressional seats, so they’ll get to draw more shapes for congressional districts than they did 10 years ago. New York, California and Illinois, among others, will draw one fewer district because they lost population. Regardless of whether they gain a seat or not, states will have to redraw all of their districts to account for population shifts within the state.


For state legislators, the number of districts depends on your state.

And there is one rule that applies to every state: There has to be about the same number of people in each district.

How to take advantage of this process: You can apportion representation based on just the subset of the population eligible to vote, rather than every person in the state, including kids and undocumented people.

Some Republicans think they can get an advantage by only counting the voting-eligible population. It’s unclear if it would actually help them. But some Republicans believe it would reduce representation for minority groups that tend to skew toward Democrats. It would also reduce representation for areas with more families with children. Any attempt to only count people eligible to vote would lead to many lawsuits.


Another way lawmakers distort this process is through so-called prison gerrymandering. Some states choose to count people in prison as part of the population of the area where they are incarcerated, instead of at their last home address. This allows lawmakers to pad the population total to justify drawing a district in areas that are often rural and sparsely populated at the expense of urban areas.

What kind of shapes are allowed?

The one rule that every state follows is that the shapes have to be contiguous. This isn’t a written rule in every state, but in the past every map states have drawn have contiguous shapes:


A rule many states have on the books is that shapes must be compact, which helps ensure districts are drawn to group together communities that are geographically near each other.


Another common rule is that shapes must follow political boundaries (like county lines) and that they must try to group together “communities of interest” which essentially means groups that have common political desires. This might be a community lobbying to keep a fossil fuel pipeline out of their neighborhood, or a community that shares a language or history. That said, only a handful of states have these rules.


How to take advantage of this process: Draw shapes that look fair, but actually favor your party.

We often assume it requires awkward shapes to gerrymander a map. But there are plenty of ways to draw shapes that are contiguous, compact and follow political boundaries – yet still heavily favoring one party. The emergence of powerful computers in the process only makes it easier to create these “stealth” gerrymanders.


Can I gerrymander to benefit my party?

In 2019, for the first time, the supreme court said that federal courts could do nothing to stop excessive partisan gerrymandering. That was a huge blow to reform advocates who hoped that the federal courts might step in.

But some state courts have stepped in to ban partisan gerrymandering.

How to take advantage of this process: There are two main strategies for gerrymandering: packing and cracking.

In a packed district, the party in power packs as many of the opposition’s voters into as few districts as possible.


Then they crack the rest, spreading thin the rest of the opposition’s voters into districts where they can never get a majority.


Can I gerrymander based on racial demographics?

No. Lawmakers are not allowed to “crack” districts where minority voters make up a significant enough portion of the population.

For example, if a Black community was cracked into several districts, it might be difficult for them to elect the candidate they want.


But if they are packed into a single district, that gives them a chance to elect their preferred candidates.

That’s why the Voting Rights Act says minority voters can argue for a district that packs them together for electoral power.


How to take advantage of this process: In the past, jurisdictions with a history of racial discrimination had to get their maps “precleared” by the Department of Justice or federal courts. That meant maps that made it harder for racial and ethnic minorities to pick their preferred candidate were struck down before they took effect.

But a 2013 supreme court ruling means that states no longer have to preclear their maps.

Ultimately this means that if a state draws a map that looks like a racial gerrymander, it will require litigation to prove that it does indeed make it harder for minority communities to elect their preferred candidate.