House Divided according to Shmoop

[RJNorton]

RE: the House Divided Speech...I think Lincoln thought the opponents of the spread of slavery were getting too complacent, and he tried to rouse them up by saying the pro-slavery forces were actually a conspiracy. I think he felt people feared conspiracies, and his use of that term was meant to force Republicans to do more in their opposition, otherwise slavery would become nationalized and be legal everywhere in the USA. Personally, I doubt there was an actual slave conspiracy trying to nationalize slavery, but Lincoln felt his mentioning this possibility would strike fear into the Republicans' hearts and force them to be more active and united in their opposition to the spread of slavery throughout the country.