After reading John Calhoun's Speech, this is the summary I came up with:
John C Calhoun's speech starts by talking about how the Union was in danger. He then goes on to talk about the reasons why the Union is in danger. It started with tensions over slavery, particularly between the North and the South, and then went on to the inequality in the government, with the Northern ideals being the main ideals of the federal government, especially in the senate. Along with these two issues, the South had issues with the restrictions with the western land, especially concerning Texas. After listing these issues, Calhoun comes back to the issue and states his opinion: that abolition and succession are the only options available to the South currently, so, in order to keep the union together, the equilibrium in senate should be fixed, and says that California can be used to find out the North's intentions for the union.
My Source for this: