Thirty years ago, the Supreme Court expanded the meaning of one of the most important civil rights laws in U.S. history — the Voting Rights Act of 1965. Among other things, the court prohibited a then-common practice among some states of spreading minorities across voting districts, leaving them too few in number in any given district to elect their preferred candidates. The practice became known as "racial gerrymandering."

The court’s solution required that states create majority-minority districts — districts in which the majority of the voting-age population belonged to a single minority. With voting that occurred largely along racial lines, these districts allowed minority voters to elect their candidates of choice.

But a fascinating development occurred in the years since. These districts, rather than giving African Americans more political power, might have actually started to deprive them of it. Majority-minority districts, by concentrating the minority vote in certain districts, have the unintended consequence of diluting their influence elsewhere. Experts say some Republican legislatures have capitalized on this new reality, redistricting in their political favor under the guise of majority-minority districts.

“Typically the goal in [packing minorities into a district] is not to reduce minority representation in the adjacent districts; it’s to reduce Democrats’ representation in those districts," said Nicholas Stephanopoulos, a professor at the University of Chicago Law School. "They’ve been arguably using the racial demographics as a way to enact a Republican gerrymander.”

The issue has gained new prominence thanks to Bethune-Hill v. Virginia Board of Elections, a case the Supreme Court agreed on Monday to hear. Virginia’s Republican-held state legislature drew its majority-minority districts to be 55 percent black. Golden Bethune-Hill, among other Virginian voters, sued the state’s Board of Elections, arguing that they used race as a primary factor in drawing district lines for the House of Delegates, which is unconstitutional under the equal protection clause of the 14th Amendment.

The state contends the redistricting process occurred fairly and legally, with bipartisan support. Republicans have generally defended their redistricting practices as following a legal practice of drawing districts in politically favorable ways — just as Democrat-controlled legislatures do.

Constitutional issues aside, what’s the practical consequence of the standard practice of "packing" districts with at least 50 percent African Americans? There are dozens of majority-minority congressional districts across the country, and many more state-level districts. They’re concentrated in the South, but can be found in states like New York and Ohio as well.

Consider an example: Imagine the minority-favored candidate can win an election in a district if at least 30 percent of voters are minorities. What harm is done by the legislators packing the district up to 50 percent minority voters?

Much like political gerrymandering, it limits black influence in surrounding districts. It would require the creation of, for instance, a 50 percent and a 10 percent black district, rather than two 30 percent black districts. In other words, the requirement would give black voters one representative of their choice rather than two.

The process of re-drawing district lines to give an advantage to one party over another is called "gerrymandering". Here's how it works. (Daron Taylor/The Washington Post)

And even if it doesn’t decrease the number of representatives the black voters can elect, it can decrease their influence in white-dominated districts. As shown in the graphic below, in a hypothetical state with five districts, packing the minority voters in at 50 percent levels rather than 30 percent leads them to lose influence in two other districts, leaving them overwhelmingly white.

In both scenarios, the minority is numerous enough to control the election in two districts. What differs is whether they have a political voice elsewhere in the state, which is ultimately necessary to pass state-wide legislation in their favor.


You might be thinking that, if only 30 percent of a district's voters are black, it will be hard for African Americans to elect their preferred candidate. But that's increasingly not the case.  The reason: the decline of racially polarized voting. Minority and white voting patterns used to be starkly divergent, but now, more whites vote for the minority-favored candidate, especially in primaries. This change came about as racial divisions, beginning with the decline of segregation and explicit racism, have faded (though obviously not disappeared), and the interests of politically like-minded blacks and whites have aligned. As a result, fewer minority voters are required for a district to elect their favored candidate.

One 2002 paper found that from the 1960s to the 1980s, districts needed to be more than 50 — some in the South as much as 65 — percent African American for their favored candidate to win the election. But today, experts place the figure between 40 and 45 percent. Stephanopoulos says it’s “certainly below 50 percent” across the country.

In majority-minority districts, minority voters are, by definition, packed beyond that threshold. Ultimately, this is detrimental to the minorities. David Canon, a professor of political science at the University of Wisconsin-Madison said, “If you have too high a percent African Americans in a House district, it does dilute the overall representation of African American interests.”

Since the minority electorate leans liberal, packing minorities has the same effect as packing Democrats, causing the district map to favor Republicans in the same way it favors whites. This key correlation has made majority-minority districts popular among Republican-held state legislatures beyond Virginia.

The partisanship is especially clear when seeing how the district lines change census-to-census. Stephanopoulos said Republican legislatures take districts "that were already electing minority representatives and pack more minority voters into them," and Democratic legislatures tend to "unpack ... minority districts." In Arizona, which has a Republican legislature but districting is done by an independent commission, "there was much less packing of minority voters than there was in the other states."

States across the country, particularly in the South where legislatures tend to lean Republican and the Department of Justice historically had stronger control over voting rights, draw these districts. Though the court is more concerned with the inappropriate use of racial classifications rather than the deprivation of minority political power, its ruling could have implications for legislatures across the country.

The Supreme Court will hear arguments in its next term beginning in October.