[126][127][128] In the view of pro-slavery Southern politicians, the Compromise of 1850 had already annulled the Missouri Compromise by admitting the state of California, including territory south of the compromise line, as a free state.[129]
Pierce had wanted to organize the Nebraska Territory without explicitly addressing the matter of slavery, but Douglas could not get enough Southern votes to accomplish this.[130] Pierce was skeptical of the bill, knowing it would result in bitter opposition from the North. Douglas and Davis convinced him to support the bill regardless. It was tenaciously opposed by northerners such as Ohio Senator Salmon P. Chase and Massachusetts Senator Charles Sumner, who rallied public sentiment in the North against the bill. Northerners had been suspicious of the Gadsden Purchase, moves towards Cuba annexation, and the influence of slaveholding Cabinet members such as Davis, and saw the Nebraska bill as part of a pattern of southern aggression. The result was a political firestorm that did great damage to Pierce's presidency.[126][127][128]
Pierce and his administration used threats and promises to keep most Democrats on board in favor of the bill. The Whigs split along sectional lines; the conflict destroyed them as a national party. 