Racial Gerrymandering vs. Racial Vote Dilution, Explained

A map of Alabama accompanied by small text that says "EXPLAINER" and large text that says "Fighting Racially Unfair Maps"

Redistricting — the process of drawing lines within a state to create federal, state and local electoral districts that reflect the population data derived from the decennial census — can be a fraught process leveraged by bad actors to pass unfair and unconstitutional maps. One way map drawers can manipulate district lines to produce certain electoral outcomes is to use partisanship to sort voters; another way is to rely on race. The U.S. Constitution protects minority voters from maps that are racially gerrymandered. The Voting Rights Act of 1965 (VRA) protects minority voters from maps that dilute their voting power. 

Given the various ways that racially discriminatory maps can be challenged in court, it can be confusing to parse out what’s going on in individual lawsuits. In this Explainer, we break down the difference between racial gerrymandering and racial vote dilution claims and when you might see them in lawsuits.

Racial Gerrymandering

What is a racial gerrymandering claim?

A state may not use race as the predominant factor in assigning voters to districts in any federal, state or local electoral maps unless it has a compelling reason to do so. If the map drawers do use race without any compelling reason, then the relevant districts are deemed racially gerrymandered.

Racial gerrymandering claims are rooted in the Equal Protection Clause of the 14th Amendment, which mandates that a state must treat individuals the same under its laws. The Equal Protection Clause is crucial for safeguarding civil liberties and voting rights because it requires states to “govern impartially [and] not draw distinctions between individuals solely on differences that are irrelevant to a legitimate governmental objective” — including race. 

The first time the U.S. Supreme Court recognized a racial gerrymandering claim was in 1993 in Shaw v. Reno. After North Carolina’s congressional map was challenged for being a racial gerrymander, the Supreme Court held that race cannot be the predominant factor in placing voters in certain districts and that courts must closely review whether the use of race — if determined to be the leading factor — is narrowly tailored and serves a compelling reason (in legal lingo, this means that strict scrutiny applies). 

Since this ruling, the Court has further expanded its jurisprudence on this area of law, holding in subsequent cases that legislative intent (and not only a district’s shape) can be analyzed to determine whether racial motivations were the predominant factors in drawing districts (Miller v. Johnson) and racial gerrymandering claims must be analyzed on a district-by-district basis rather than the entire state (Alabama Legislative Black Caucus v. Alabama). The Court reaffirmed its prior applications most recently in 2017 in Cooper v. Harris and Bethune-Hill v. Virginia State Board of Elections.

How does a plaintiff successfully prove a racial gerrymandering claim?

There are a few steps to proving a map was impermissibly drawn using race. First, a plaintiff must show that race was “the predominant factor motivating the legislature’s decision to place a significant number of voters within or without a district.” This means proving that other factors a state might consider when redrawing lines, including preserving compactness of districts, maintaining political subdivisions or communities of interest and/or promoting partisan advantage, were all secondary considerations to race in a map’s configuration.

If the plaintiff successfully proves that race was the most important factor behind a map’s lines, then strict scrutiny applies. This means that the map drawers now have to prove that the predominant use of race to draw districts serves a compelling reason and is “narrowly tailored” to fit that specific interest. One compelling reason that states often point to in favor of race-based sorting of voters is the need to comply with Section 2 (to be discussed further below) and, before it was gutted, Section 5 of the VRA.

In the Courts: Cooper v. Harris

In 2013, voters challenged two of North Carolina’s congressional districts for being racial gerrymanders that intentionally “packed” Black voters in order to dilute their voting power across the state. A lower court found that Republican legislators “assigned race [as] a priority over all other districting factors” and concluded that the Legislature “packed” Black voters into these districts despite the fact that this was not necessary to comply with the VRA — meaning there was no compelling reason for the Legislature to use race. North Carolina appealed the decision to the Supreme Court, which affirmed the lower court’s finding and ordered the Legislature to adopt a new map. Writing for the majority, Justice Elena Kagan said “by no means…will we approve a racial gerrymander whose necessity is supported by no evidence.”

Racial Vote Dilution

What is a racial vote dilution claim?

A racial vote dilution claim is brought against a map when a state’s minority voters cannot elect the candidate(s) of their choice, often because the map drawers “packed” the voters into one district and “cracked” them among other districts in order to weaken (or dilute) their collective voting power across a state. This means that a vote in one district has less of an impact on the outcome of an election than a vote in another district because of the way districts are drawn — a tactic that can and has been weaponized to minimize the voting strength of minority voters. Section 2 of the VRA is designed to protect against this type of race-based vote dilution and can be leveraged against federal, state or local electoral maps.

How does a plaintiff successfully prove a racial vote dilution claim?

In a 1986 ruling, the Supreme Court established three criteria (known as the Gingles factors) for proving a pattern of racial vote dilution: 1) the minority group in question must be “sufficiently large and geographically compact” to elect a candidate of its choice; 2) the minority group must be politically cohesive (meaning they typically vote in a similar manner) and 3) the majority group must be politically cohesive enough to defeat the minority group’s preferred candidate(s). Importantly, a plaintiff does not need to show discriminatory causation or intent in order to prove vote dilution claims; it is enough to show that the districts result in the dilution of minority voting strength, even if that was not the map drawers’ express intent. 

Courts also look at the “totality of circumstances” in order to determine if district lines result in racial vote dilution. Based on the legislative history leading up to Section 2’s enactment, there is a list of so-called “Senate factors” used to analyze whether a map denies minority voters “an equal opportunity to participate in the political processes and to elect candidates of their choice.” These factors include analyzing:

  • The state’s history of racial discrimination in voting, 
  • The level of racially polarized voting, 
  • Any racial discrimination affecting education, employment or health among the minority population that might limit their ability to participate in the democratic process, 
  • If political campaigns in the state have relied on overt racial messaging and
  • The representation of the minority group in elected positions in the state.

If a court finds that the plaintiff has successfully proven all three Gingles factors and the totality of the circumstances weigh in their favor, the plaintiff has won their Section 2 claim. Following a Section 2 violation, a court will often order the state to redraw districts to ensure that minority voters can adequately elect the candidates of their choice. For example, if Black voters were previously “packed” into one congressional district and “cracked” among the state’s other congressional districts, even though they can constitute a majority of cohesive voters in two districts, a court would likely order the state to redraw its congressional map to contain two majority-Black districts.

In the Courts: Ardoin v. Robinson

After Louisiana’s congressional map was redrawn with 2020 census data, two lawsuits were filed alleging that the map dilutes the voting strength of Black residents in violation of Section 2 of the VRA because it fails to include a second majority-Black district. A lower court agreed with the plaintiffs, blocking the map for likely violating the VRA because the Black population in Louisiana is sufficiently large and geographically compact enough to constitute a majority in two congressional districts and Black Louisianans vote cohesively as a bloc. The Supreme Court reinstated the map and paused the case until it decides a similar case about Alabama’s congressional map in its 2022 term, but the lower court’s decision provides a helpful framework for analyzing Section 2 claims.

Racial gerrymandering and racial vote dilution claims can be used to successfully block discriminatory maps.

All legislative and congressional maps must comply with relevant state and federal laws, including the 14th Amendment of the U.S. Constitution and the VRA. Depending on the context, racial gerrymandering and racial vote dilution claims can be brought either separately or in tandem. For the latter, a plaintiff might argue that map drawers went out of their way to intentionally use race in order to ensure that there were no minority opportunity districts in violation of Section 2. However, the interaction of racial gerrymandering and racial vote dilution claims may only get more complicated when the Supreme Court decides Merrill v. Milligan in its 2022 term.