[HandyDandy]

For example. The Constitution required the federal authority to return slaves to people for whom their labor was due according to the laws of any state.

Nope. Sorry. That is incorrect. In point of fact, it is complete and total, utter bullsh*t. Nowhere in the US Constitution does it require the “federal authority” to do any such thing. Again, you are broadbrushing the Fugitive Slave Clause with what the Slave Powers later turned it into. Remember the Fugitive Slave Act?.....the Fugitive Slave Law?.... The Compromise of 1850?......perhaps the Dred Scott Decision rings a bell? It was The Southern Slave Aristocracy that made a Federal Case out of Slavery.

[DiogenesLamp]

Nope. I'm accurately stating what it always required. Liberal states tried to "living constitution" it away with their bullsh*t made up meanings and their "sanctuary city" like defiance of federal authorities, and the Federal Judiciary simply patched up excuses and looked the other way because they didn't like the agreement either.

The North routinely and deliberately ignored a requirement of the US Constitution because they didn't like it. It's that simple.