Stephen Douglas was the incumbent Democratic senator of Illinois and Abraham Lincoln was his Republican challenger. (Faragher, 2006, 422) Lincoln held an antislavery stance and felt that slavery was a moral wrong. (Faragher, 2006, 423) Douglas did not appear to take a definitive stance on slavery. He thought that he was solving the slavery problem by proposing that the status of slavery in the new territories be decided by popular sovereignty. (Faragher, 2006, 434)
In all there were seven debates held throughout Illinois, and the turnouts emphasized the enormity of the political crisis. At every debate there were between 10,000 and 15,000 attendees. The second debate was held in Freeport on, which is along the northern border of Illinois, and Douglas’s stance helped him win re-election but it also alienated him from the Southern Democrats.
Below is the link to an article written on August 27th, 1858 by John T. Morton of the Quincy Dailey Whig and Republican.
http://lincoln.lib.niu.edu/cgi-bin/philologic/getobject.pl?c.2255:1.lincoln
I found this article, that has been digitized, on the Northern Illinois University’s library website. What I found interesting was how precise Lincoln was with his answers while Douglas used vague language for the most part. Senator Douglas seems as though he did not want to take a wholehearted stance on the issue of slavery in the new territories. Is it possible that Douglas was not being clear as a way to appeal to all voters? If that was the case then it helped him win re-election, but it also helped Abraham Lincoln gain popularity and shortly become President when the South succeeded from the Union.
Below is the results from the 1858 campaign for U.S. Senator of Illinois in which Stephen Douglas won.

Image Source: Abraham Lincoln Historical Digitization Project