Final answer:
Chief Justice Taney claims that Scott, as a black person, cannot be a citizen and therefore cannot sue in federal court. He argues that the Constitution supports slavery and that Congress cannot ban slavery in the territories.
Step-by-step explanation:
In the passage, Taney makes the claim that Scott, as a black person, cannot be a citizen of the United States and therefore does not have the right to sue in federal court. Taney argues that the Constitution upholds slavery and that Congress does not have the authority to bar slavery in the territories, making the Missouri Compromise unconstitutional.