I’ve tried to make the case that the very process of bailout established a continuing connection between current conditions and the 2006 formula for section 4.  Here, Morgan Kousser presents one of the alternative continuing connections, with detailed data showing the incidence of voting rights actions and the (formerly) covered jurisdictions.  And he pulls it all together as only Morgan can:

The Supreme Court’s Shelby County v. Holder decision on Tuesday essentially cast aside the key component of the nation’s most important civil rights legislation.

The five “conservative” justices castigated Congress for putting too much emphasis on history by failing to update the “coverage formula” in Section 4 of the landmark Voting Rights Act of 1965.

. . .

Congress did not update the formula because it knows it still works. The comprehensive database that I assembled proves this. Consider, from 1957 through 2006, almost 94 percent of all voting rights minority lawsuits, legal objections and out-of-court settlements occurred in jurisdictions now subject to federal oversight under the Section 4 formula.

More here.