right, the supreme court could absolutely decide that the states get to decide.
think of it this way.. its up to the supreme court to decide how the law was intended. the only specific roles mentioned in the constitution are where the 2/3rds of congress can 'remove the penalty of being an insurrectionist'.. this implies that the states (via congress) have the right to both decide who, and who does not get marked as 'insurrectionist'.
the house cant decide for individual states, and so each state could be left to decide for themselves... leaving it to an action of congress to undo.