Some people probably already know this. This is a map of all the results, if the Democrats never split up into the three different factions, and supported Douglas.Abraham Lincoln 169 Electoral/39.6 PopularStephen Douglas 134 Electoral/60.3% Popular
Despite losing the popular vote by almost 20 points, Abraham would still win the presidency. The South would at this point have a real reason to secede from the Union, since even a unified Democratic Party, with the overwhelming support of the people, failed to block a Republican surge.
Ohio, Illinois, and Indiana would be the closest states in this scenario. For Douglas to win, he would either need to take Ohio, or the combined electoral votes of Illinois and Indiana. Just proves the power of the Northern States in those days.