Answer:
the lack of citizenship for enslaved people
Step-by-step explanation:
Scott v. Sandford basically argued Whether or not African American were allowed to sue in a federal court.
The constitution only granted that right to sue to the citizens of of United States. But the supreme court ruled that the African American were brought into United States as a form of 'property'. So, they're not considered the African American as 'People' that could gained citizenship.
Therefore, Scott was not allowed to sue in a federal court.