"A precedent of this Court should not be treated like a disposable household item—say, a paper plate or napkin — to be used once and then tossed in the trash."

"But that is what the Court does today in its decision regarding North Carolina’s 12th Congressional District: The Court junks a rule a...

"But that is what the Court does today in its decision regarding North Carolina’s 12th Congressional District: The Court junks a rule adopted in a prior, remarkably similar challenge to this very same congressional district."

Writes Justice Alito in the dissenting opinion to Cooper v. Harris, a 5-3 opinion released today.

In Easley v. Cromartie, 532 U. S. 234 (2001) (Cromartie II), the Court considered the constitutionality of the version of District 12 that was adopted in 1997. That district had the same basic shape as the district now before us, and the challengers argued that the legislature’s predominant reason for adopting this configuration was race. The State responded that its motive was not race but politics. Its objective, the State insisted, was to create a district in which the Democratic candidate would win. Rejecting that explanation, a three-judge court found that the legislature’s predominant motive was racial, specifically to pack African-Americans into District 12. But this Court held that this finding of fact was clearly erroneous. Cromartie II.

A critical factor in our analysis was the failure of those challenging the district to come forward with an alternative redistricting map that served the legislature’s political objective as well as the challenged version without producing the same racial effects. Noting that race and party affiliation in North Carolina were “highly correlated,” id., at 243, we laid down this rule:

“In a case such as this one . . . , the party attacking the legislatively drawn boundaries must show at the least that the legislature could have achieved its legitimate political objectives in alternative ways that are comparably consistent with traditional districting principles. That party must also show that those districting alternatives would have brought about significantly greater racial balance. Appellees failed to make any such showing here.” Id., at 258.

Now, District 12 is back before us. After the 2010 census, the North Carolina Legislature, with the Republicans in the majority, drew the present version of District 12. The challengers contend that this version violates equal protection because the predominant motive of the legislature was racial: to pack the district with African-American voters. The legislature responds that its objective was political: to pack the district with Democrats and thus to increase the chances of Republican candidates in neighboring districts.

You might think that the Cromartie II rule would be equally applicable in this case, which does not differ in any relevant particular, but the majority executes a stunning about-face. Now, the challengers’ failure to produce an alternative map that meets the Cromartie II test is inconsequential. It simply “does not matter.”

This case came out 5-3 because Justice Gorsuch did not participate, and Justice Thomas concurred. Thomas's concurrence sets him apart from the rest of the majority (Kagan, Ginsburg, Breyer, and Sotomayor) because he thinks Cromartie II got it wrong and it's "a welcome course correction" to "confine[] it to its particular facts."