For a majority of northerners, the most outrageous part of the supreme court's ruling in the dred scott case was

that Congress had never had the power to prohibit slavery in any territory.

Explanation:

The Dred Scott Case against Sandford (also known as The Dred Scott Case) was a crucial lawsuit in the history of the United States, resolved by the Supreme Court of that country in 1857 in a decision that prohibited any inhabitant of African descent , whether they were slaves or not, the right to citizenship and that took away from Congress the authority to ban slavery in the country's federal territories.

the united states has a federal government. the president is the head of the federal government of the united states. however, each state forms its government for administration purposes. the powers of the state governments are exercised within restricted state boundaries. and citizens participate in this government by voting.