For number two, I would say that the Dred Scott decision, and its obvious activism, propelled the north to create the Lincoln candidacy — a politician that, at Coopers Union, could answer the question of territorial slavery and how it could be governed by federal poser during the growth of the Union.
Dred Scott ==> Cooper Union ==> South Carolina succession ==> Fort Sumter Deadlock ==> Mass Succession
Buchannan set the thing in motion by pushing the Court thinking that such a decision could take the problem away from requiring a devisive Congressional soultion.
Judicial fiat, solves nothing in self-government.
I can't believe I missed Dred Scott in all of this. That's like running a marathon and forgetting to tie your shoes. Thanks for catching that.