For example, in N.C. 40 of 100 counties are, or were, "covered" under Sec. 5:
Congress, who placed these counties on this list in 1965, can draw up a new list (or make federal pre-clearance universal).
Preclearance comes either from a Three-Judge federal panel or from the DOJ Civil Rights Division (or both, in some cases.)
There are some redistricting plans presently in litigation, and how they are or are not affected I don't yet know.
Without Section 4, Section 5 is almost meaningless if I understand it completely.
Where can one find the “preclearance-affected” counties map for other states, such as Texas?