Or if you prefer, Alabama would have to accept the property rights of Iowa. Southern slave holders would have to accept NY limitations on property rights when the slave holders brought their slaves to the Hamptons to get away from oppressive southern heat, and when they did that, their slaves would become free. That is what the owner of Dred Scott did: He took a slave to a free state, and wanted to overturn state limitations on property rights.
Too bad it took a war to correct that bad court case.
Dred Scott, horrible as it was as a legal ruling, was inevitable. If the nation took the political option of the Lewis Cass/Stephen Douglas position (”popular sovereignty”), the South would lose because it would soon be outnumbered by new free states and outvoted, and eventually would lose the protections of slavery.
If it took the Daniel Webster position that Congress had authority over slavery, the South would lose, for the same reasons: the North would, with its population growth, overwhelm the South in the Senate and House.
Only John C. Calhoun’s position-—that only a preexistent state government could abolish slavery-—would preserve slavery, so that is what Taney’s Court went with. That made slavery the de facto position of every new state, which was also unacceptable to the vast majority of Americans.
When Taney declared that Negroes were not people, he sealed the quicker and bloodier doom of slavery, but I don’t see how it was going to be accomplished without a war.