Dean Erwin Chemerinsky in SCOTUSBlog :

When is it ever appropriate for the Supreme Court to decide that a federal law is unconstitutional because it is no longer needed?

This question arose during the oral arguments on Oct. 15 in Louisiana v. Callais , involving the constitutionality of Section 2 of the Voting Rights Act….. But it is not obvious why it is the court’s job to decide when a problem is over, and it is even less clear how the court should go about making such an inquiry….

But if the court rejects such deference to Congress, then there must be a basis for the justices deciding the level of racial discrimination in voting sufficient to justify the provisions in the federal law and also for its determining whether that threshold is met. The problem, though, is t

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