court cases of that era were moving towards the “you cannot prohibit slavery in free states” position
To my knowledge, before 1860 no such ruling was ever issued by any court in the U.S. If you can cite such a case, would appreciate it.
Even the Supreme Court recognized the legal existence of “Free” states in the Scott v. Sanford.
“you can’t prohibit someone from coming into your state with their slaves.
To live there, Yes you can. If slavery is illegal in New York State, you are not denying an Alabama slave owner any of the privileges or immunities that a citizen of New York State enjoys. He can buy land, own horses, sue in court, be tried by a jury, own fire arms etc, as any New York citizen. Since it is illegal for a New York citizen to keep a slave in the State of New York, the Alabama slave owner cannot keep a slave legally in New York State.
That does not violate the immunities and privilege’s clause
All states were required to recognize slaves as legal property. That's that Article IV thing. Denying someone the use of their "property" is a fifth amendment violation. You didn't address that point. Slaves are being treated as a "special class" that is undefined in the constitution.
As for court cases moving in that direction, they fellow just claimed there were some, and told me to check out the Wilmont proviso, though I'm not sure what connection he wanted me to see regarding that.
I may look and see if I can find him again and ask for a clarification and some examples.