Again, why accept half a loaf when you've claimed the whole loaf for yourself? In the eyes of the southern leadership the greatest threat to them was limitations on the expansion of slavery, for with every new free state there was a new pair of anti-slavery senators. And as the free states grew the disproportionately large number of southern congressmen became less and less influential. That was the fear, not an end to slavery. That was the goal of the Republican party, containment and limitation of slavery and not ending it where it was. They knew that they could never accomplish that so long as the slave states held together.