[DiogenesLamp]

So there is actually a better case that the South seceded because they didn’t get the expansion of federal power they wanted.

You mean they took the choice of having even less Federal power? How does that make any sense?

[Sherman Logan]

In 1860 southern Democrats insisted on a pledge in their party platform that a Federal Slave Code protecting slave property would be imposed by Congress on all territories, and that federal troops would be used if necessary to enforce it.

The idea being to get around Douglas and his notion that territories in could exclude slavery by simply refusing to enforce it. Southern Democrats insisted this out be removed and that the Democratic Party agree to actively support the expansion of slavery. This would of course be an expansion of federal power.

Northern Democrats refused, and southern Democrats walked out of the convention, twice. Guaranteeing Lincoln’s election and therefore secession.