What did dred scott base his claim freedom on?

His travels and residences in free areas.

Explanation:

The case Dred Scott v. Sanford was a landmark decision of the Supreme Court. In this case, Dred Scott, an enslaved black man, sued in court for his freedom. He argued that his owners had taken him from Missouri into the Missouri Territory, which was a "free" territory. The court ruled that Scott could not sue in court as he was not considered an American citizen due to his African ancestry, regardless of whether he was a slave or not.

polling is a process and the outcome is not involved in the process itself.

the outcome, which is an unfavorable rating for a particular candidate is not affected by the mechanical process of polling.

it rather depends on the number of people voting in favor of the candidate.

this is an outcome of people's preferences.