God forbid that anyone should be lawyerly regarding the law.
Whatever way they "understood it" is irrelevant. Courts have ruled over and over again that "intent" is less relevant than the text of a law. Who can say what was the intent of the ratifying conventions in Virginia or South Carolina when they approved the law?
Perhaps they understood it to mean exactly what it says; That no state law can interfere with returning a laborer to the person to whom the labor is due in accordance with the laws of his home state.
Perhaps you are the one trying to do the clever lawyering by asserting a meaning that cannot be discerned from the text itself? You put conditions on the law that are not apparent from the text of the law.
Sorry, FRiend, but respect for Founders' Original Intent is what marks the difference between Free Republic-type conservatives and liberal/progressive activists.
If you come down on the liberal/progressive side of that then you have no business pretending to be conservative.
Respect for Founders' Original Intent is what made the late Justice Antonin Scalia a model for what we expect from President Trumps' nominee to replace him, Neil Gorsuch.
And your failure to grasp the significance of Original Intent, DiogenesLamp, could be what's been driving you politically insane.
The reason is simple & obvious: over time, words taken out of context can be twisted to mean just about anything, and that describes DiogenesLamp's interpretations of both Declaration of Independence and US Constitution.
Once you cast-off the anchor of Original Intent, then your boat-load of interpretations can be blown wherever the winds of current fashion may take them.
In this example, Founders' Original Intent is utterly clear and contrary to the generations-later interpretations of Chief Justice Taney or our own DiogenesLamp.
DiogenesLamp: "Perhaps they understood it to mean exactly what it says;
That no state law can interfere with returning a laborer to the person to whom the labor is due in accordance with the laws of his home state."
But the Constitution's word you keep avoiding, like Count Dracula shrinking from the Cross, is "escaping".
The Constitution here clearly refers to Fugitive Slaves, not to those taken by their "owners" into free states.
This interpretation was clearly understood at the time and no Founder challenged states-rights to abolish slavery within their own borders.