Final answer:
Stephen Douglas favored popular sovereignty during the Lincoln-Douglas debates, arguing that the decision to permit or prohibit slavery should be made by the residents of each territory, a stance embedded in the Freeport Doctrine.
Step-by-step explanation:
Stephen Douglas's Position in the Lincoln-Douglas Debates
During the famous Lincoln-Douglas debates of 1858, Stephen Douglas championed the idea of popular sovereignty. This concept held that the residents of a territory should have the right to decide whether to allow slavery. Douglas's stance, known as the Freeport Doctrine, suggested that while a territory might have the ability to deny slavery by not passing laws necessary for its establishment, it was a position that caused significant controversy within the Democratic Party and played a part in splitting it. The core of Douglas’s position was that local self-government was essential for America's freedom, allowing each territory to decide the legality of slavery for itself.
Douglas's adherence to popular sovereignty put him in conflict with the Dred Scott decision, which stated that Congress did not have the authority to prohibit slavery in the territories. His views also drove a wedge between northern and southern Democrats, as the latter were largely pro-slavery and felt threatened by any mechanism that could lead to slavery's prohibition in new territories.