My understanding is that the court found that the VRA included extra-constitutional provisions that stomped on those states and at that time 1965 it allowed them because of the extra-ordinary discrimination going on,
So the 2006 fwightened wabbit GOP congress + Bush comes along and just re-authorized it as is without even looking at it because they were terrified of being labelled.
I remember reading in NR a contributor saying the congress needs to disable those specific parts, but they didnt.
Sorry, to finish
and that was the basis for this court to throw it out, the congress of 2006 failed to justify it when they re-passed it.