Why was Stephan Douglas important during the election of 1860?

Stephen Douglas was a key figure in the 1860 presidential election as the Democratic Party's nominee, representing the Northern faction. His support for popular sovereignty, which allowed territories to decide for themselves whether to allow slavery, highlighted the growing sectional divide in the U.S. Douglas faced significant challenges, including a split in the Democratic Party, which ultimately weakened his campaign. His candidacy underscored the tensions between North and South, setting the stage for Abraham Lincoln's victory and the subsequent secession of Southern states.